Okay I'll say this again and then I'll drop it.
Consider winterizing your RV and just carry in what water you need for the weekend or week.
Believe me, if you leave water in the lines you will have freezing and you will have leaks. Small lines will freeze in a matter of hours if not protected properly, and it's hard to do well. Electric heating systems to keep them from freezing will inevitably fail at some point.
When I was a kid we had a camper in the mountains with a well and everything. Every spring we fixed leaks.
It's a lot simpler and less worry just to winterize and carry water in as needed.
There. Old guy has said his peace.