> Saw everything but Perth and Darwin.
I wouldn't consider those "sights". Nor would I say it's possible to "see everything" else in 2 months.
Traveling slower doesn't mean sitting around, it means appreciating the more intimate aspects of the area.
For example, rather than hitting the interstate between cities, I suggest you look at books like this series: https://www.amazon.com/dp/B0892CPPV4 or https://www.amazon.com/dp/B08RJBP92Z
You might just find that rushing everywhere and checking the, "I've been there box" to be a bit unfulfilling.