Milli and I went on a road trip just after getting our first Tesla, #000064, to many of the areas you outline. At the time, there were NO SUPERCHARGERS in the entire country, so RV parks were the order of the day, some free, most wanting ten bucks for their slow service. We found that RV parks are not usually placed near any businesses, so we often would GET TO walk a couple miles into town while our car charged. SOMEtimes the motel would have RV outlets. Still, we made it to where we wanted to go, visited with relatives, and had a great time, even without using "A better route planner" (what?) or other nav helpers. Still have never used ABRP to this day, after over 250,000 miles on four Teslas. Some things you don't need. With the current map on the display, and tons of available charging shown, it's not hard.
And this was before my new 400 mile range Model S.