sunshine_eggo
Happy Breffast!
The goal is to have as little maintenance as possible, so I won't want to add propane to my RV constantly. The built-in tank only holds about 15 lb., so I would like to use a mini-split for both heat and cold.
That's a really small tank. Are you sure? The typical grill tank is 20lb. is it smaller than that? Do you maybe mean it holds 15 gallons? That's closer to 2X 30 lb bottles.
Summer cooling is likely not an issue, but winter heating will be. We can run our garbage rooftop RV A/C for about 7-8 hours on 6kWh usable of FLA and 3kW of solar.
Assess your actual heating needs. Is your climate such that you likely won't need heat in the middle of the day?
With outside temps of 25°F, we are comfortable with the propane furnace preventing the pipes from freezing keeping the interior at 45°F and using an electric blanket to keep us very very toasty. Mornings are brisk, but as you know, RV insulation sucks, and we take on a lot of heat even when it's only ~50°F outside.