We "wintered over" in Montana twice. Once in a 32 foot class A, and once in a 32 foot fifth wheel.
Both times I fabricated the water line out of hard copper tubing, heat taped and insulated with fibreglas pipe insulation. The water faucet was heated and insulated by the park owners for year-round use.
In the motorhome, I bought a 100 pound propane cylinder and a 12 foot hose. I used the motorhome regulator. I would load it in the truck and take it to the nearby Flying J to get it filled.
In the fifth wheel, I rented an 80 gallon tank (100 gallon, 80 gallons usable). The propane company delivered the tank, hooked it up, filled it, and kept it full all winter. That was wonderful.
The water line for the fifth wheel was nearly 40 feet long, as was the sewer line. No problems.