super_camper has a profile indicating he has a unit (2006 Jayco Greyhawk) that advertises:
"Holding and fresh water tanks, ducted or radiant-heated"
To me that would mean all his PVC pipes, valves and drains are all in a heated enclosure. If the OP RV is so equipped then super_campers advice may be applicable.
We have a unit that is fully enclosed and receives heat from both the LPG furnace and the engine heater. We still choose to not dewinterize until we reach a warmer climate just in case we get stranded for some unknown reason while enroute. We travel at end of December and end of March.