I am going to be spending alot of the winter in my 1994 Fleetwood Bounder. I just got it last March and haven't dealt with any cold weather in it. I have city water source and I am planning to put heat tape on the supply line. Will the interior lines of the RV be safe from freezing at about 20 degree weather? What about the drain lines. It will be in the same spot except to move to go refill the on board propane tank so I plan in putting something in place to keep air from getting under the RV. I would really like to make a fitting and a hose to attach to a different propane tank so I wouldn't have to move it at all. Has anyone here ever tried anything like that. I am new to this and just seeking some good, sound, safe advises. Thanks in advance.