Absolutely. Adding quilts does the trick. Plus think sleep system, not just bag/quilt. An inner tent as opposed to a mere net tent will give you a lot more warmth per weight than a down bag!
http://www.ipernity.com/doc/charly13/49112268/in/album/1239318
This, with a good battery:
ECEEN Solar Charger Foldable Solar Panel Charge for iPhones, Smartphones, Tablets, GPS Units, Speakers, Gopro Cameras, and Other Devices (13W with Net Pocket) https://www.amazon.com/dp/B07LGVHHHN/ref=cm_sw_r_cp_api_i_oVMdFbZT3QGSQ