If you can put some wind-block material for skirting around the bottom of the RV that will help your heat situation.
Sanitize your water system and hose. Use a drinking water grade hose. Use the hose to fill from a freeze-protected faucet, then remove the hose and store it in a heated area (in the house somewhere.)
You also have to think about your waste tanks. You can't leave a sewer hose connected. Flush thoroughly when you dump, and then put about a gallon of RV antifreeze down to protect the valves.
This whole thing would be a lot simpler if you could wait until warmer weather to do the remodel. Spring or fall would be much better. I've given this some thought, as I might be in the same boat in a couple of years.