Man, tough scenario. If punching holes in the walls or going through the attic for hard wired runs to a meshed network system is out of the question then I would recommend looking at an powerline setup.
This essentially uses the powerlines in your home as data cables.
I've heard good things about TP-Link Powerline Decos
You could try a TP-Link extender, but I would add another M5 node with a powerline Ethernet adapter for wired backhaul. They make a Deco system with powerline networking built-in: https://www.amazon.com/dp/B081ZWJ6FX?ref_=cm_sw_r_ud_dp_CGDQJJRHM1M4RH4SXJ47
I don’t know your budget, but that integrated system is still WiFi 5, so I would consider if this is a good time to upgrade to WiFi 6 and use a powerline Ethernet adapter to put a node in the garage.
This one from TPLink is actually a hybrid that 7se both mesh but also a secondary Powerline feed. Basically the Powerline will kick in when the mesh connection between two of the units is lost.
Poweline speeds vary depending on many factors of your homes electrical and are usually going to be less than what you will get thru the wifi mesh connection.
But this hybrid kit covers both bases.
TP-Link Deco Powerline Hybrid Mesh WiFi System(Deco P9) –Up to 6,000 sq.ft Whole Home Coverage, WiFi Router/Extender Replacement,Signal Through Walls, Seamless Roaming, Parental Controls, 3-pack https://smile.amazon.com/dp/B081ZWJ6FX/ref=cm_sw_r_apan_i_DAPRRCZMQVS0YYN49XWS
Well, then MY recommendation if you don’t want to run Ethernet (I would) would be to go with a TPlink system.
While traditional mesh Wi-Fi systems conenct to each other over Wi-Fi, these are one of the few that can also use the electric wires in your wall to connect to each other. Wired is always the most reliable.
TP-Link Deco Powerline Hybrid Mesh WiFi System(Deco P9) –Up to 6,000 sq.ft Whole Home Coverage, WiFi Router/Extender Replacement,Signal Through Walls, Seamless Roaming, Parental Controls, 3-pack https://www.amazon.com/dp/B081ZWJ6FX/
Honestly, It depends on how fast you need it. For something that is just useable, a WiFi extender in between the areas would work. For something better, a power line system with another WiFi AP on the other end could work. And with that home layout a mesh system could work, provided you have them wired together. TP-Link does make a mesh system that has power line and WiFi for mesh, that might work in your case. (TP-Link Deco Powerline Hybrid Mesh WiFi System(Deco P9) –Up to 6,000 sq.ft Whole Home Coverage, WiFi Router/Extender Replacement,Signal Through Walls, Seamless Roaming, Parental Controls, 3-pack https://www.amazon.com/dp/B081ZWJ6FX/ref=cm_sw_r_cp_api_glc_fabc_QDKGFP7RKRYVWNDHE21M ). It’s a little above your budget, but if you could find a place selling only two of them it might be cheaper.
I have the 150 Mbps package. Costs about equal to Cox, but better consistency and reliability. Handled 3 kids doing remote school and me and the wife doing our thing. Modem they supply has WiFi built in, but there were dead spots in dining room and other parts of the house, so I got a hybrid-mesh wifi with 3 extenders. I think they have an option now where you can get the whole house wifi with extenders that works with the modem, but not sure.
Cox would have problems when it rained hard, which is not uncommon in these parts and I would often have to reboot the cable modem.
Also, when Covid lock-down hit, there were so many complaints from neighbors about Cox internet. Must have had too much traffic with all the kids doing school at the same time. Glad I changed when I did (Early Feb 2020).
Just found this:
www.amazon.com/TP-Link-Deco-Powerline-Replacement-P9/dp/B081ZWJ6FX/ref=sr_1_3
Dr. Evil Smile. But to answer your question I have not used the product but yes, looks like it integrates the router so no need so you can go direct into white-port. You would not need an AP in between, the devices take care of managing the mesh & backhaul.
get a 1Gbit powerline mesh
https://www.amazon.com/TP-Link-Deco-Powerline-Replacement-P9/dp/B081ZWJ6FX
MESH its a good idea to use it QOS priority engine so VOIP will be passed first... SL router still dont have it and any download can kill your voice. No need to buy newest and expensive cz they made for Gigabit Fiber speeds. $130-200 range for 3 pack. !! This one can use Gigabit powerline thing as a backbone, there is refubs for $135 https://www.amazon.com/TP-Link-Deco-Powerline-Replacement-P9/dp/B081ZWJ6FX/ref=sr_1_26?keywords=asus+mesh&qid=1653798619&sr=8-26 !!
ALSO any router with extender/wisp function will work, better to connect via 5Ghz to give it some breathing room. 90% routers can handle extender work via openwrt firmware, but its sometimes hard to install.
Why have just one?
TP-Link Deco Powerline Hybrid Mesh WiFi System(Deco P9) –Up to 6,000 sq.ft Whole Home Coverage, WiFi Router/Extender Replacement,Signal Through Walls, Seamless Roaming, Parental Controls, 3-pack https://smile.amazon.com/dp/B081ZWJ6FX/ref=cm_sw_r_cp_api_i_T6D1RQGK5602JEZ0KP2N
ASUS ZenWiFi AX Hybrid Powerline Mesh WiFi6 System (XP4) 2PK - Whole Home Coverage up to 5,500 Sq.Ft. & 6+ Rooms for Thick Walls, AiMesh, Free Lifetime Security, Easy Setup, HomePlug AV2 MIMO Standard https://smile.amazon.com/dp/B07WJ47M95/ref=cm_sw_r_cp_api_i_99AFJSVHKEPS428EWRCJ
Keep in mind that I too am waiting on an ethernet adapter dongle, so this is somewhat theoretical, though I do have a fair amount of experience dealing with ethernet and wifi over the decades. With that said, there are several ways to accomplish what you seem to be wanting, ie wifi throughout the house and a wired port in your study, and that you have no actual desire to run cable through the thick stone walls of your house.
If this is the case, then there are several options, the first choice you need to make is do you keep using your Starlink router as a router, or do you bypass it and use your own router (yes you can do either way, even though one of the other posters says otherwise, though I am inclined to say use your own router due to flexibility options).
If I were in your situation I would opt to try the easy method before running ethernet cable through thick stone walls, and that is to try an Ethernet over Powerline Mesh wifi system. Such as the TP-Link Deco P9 https://www.amazon.com/TP-Link-Deco-Powerline-Replacement-P9/dp/B081ZWJ6FX each unit acts as a wifi access point and has a pair of wired ports, which communicate to each other using ethernet over power line. The minor downside to this setup is that ethernet over power line is slower than ethernet over twisted pair cable, though for internet access in this case Starlink will still be the bottleneck at circa 200 mbps.
TP Link Hybrid Mesh (Deco P9) https://www.amazon.com/gp/product/B081ZWJ6FX
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I have put these in two relatives homes that had really tough WiFi issues, and they work well. Not WiFi 6, but this would solve your out building issue nicely.
I think you might be pleased with mesh performance. You won’t know unless you try. Check out https://www.amazon.com/dp/B081ZWJ6FX/ref=cm_sw_em_r_mt_dp_dl_FMM52SM0C2QHNH200XFT for an option that combines mesh and powerline.
Did you consider TP Link Deco M9 power line hybrid mesh , it is a mesh WiFi, but it also gives you an Ethernet backhaul over power line.
I personally use TP link Deco M5 and used TP-link’s power line Ethernet in the past (my new setup has in wall wiring), but the combination serves as a one-stop-shop for what you need.
The setup can be managed easily with TP-Link’s deco app, also you can add a co-manager to manage the location, all from a mobile application. You can manage from anywhere as long as your phone has an internet connection and your main deco has access to the internet.
The setup that served me very well: I used my ISP’s router to connect (using FTTH) to the internet, then this router had a static IP address entry to the main deco’s Ethernet port, the main deco was configured in router mode where it then took care of the internal setup.
I always had a backup so when things go south with my deco setup, there is at least the option to use the ISP’s router WiFi until I fix my deco setup. It have been more than 2 years and I never had to use that backup plan.
Looks like the only CM8200 models I can find are used from ebay. Even with the 3270 do you think something like this would be more than enough? It's a little cheaper than the Eero 3-pack.
What do you guys think of this? https://www.amazon.com/TP-Link-Deco-Powerline-Replacement-P9/dp/B081ZWJ6FX/