Look for off-grid ideas to keep costs down from lack of utilities. Your RV may already have everything needed, with just some way to supplement for long-term dry camping.
As suggested, solar for electric. Generator for big loads.
If no water well, can get a water tanker periodically. If in area where permissible, rainwater harvesting. Or if near a water source, load up periodically if permitted or for a fee (Just don't do a Tom Selleck water hydrant tanker fill.).
In lieu of a septic system, go with a composting toilet and graywater disposal system. This is better for environment.
Propane tank.
More difficult is Internet access. Worst case, satellite.