American coaches are pretty high end so suspect you have some heat ducted to your wet bay (where your domestic water pump resides). If you are running your heat sufficient to be comfortable in the coach, you should be fine. If your water heater has the heat exchanger attached to it that lets hot engine coolant to heat the water while you are driving down the road, that will be fine.
Do you have a LP furnace or Hydro Hot? If Hydro Hot (hydronic heating system), you probably have a heat exchanger in the wet bay. Run the Hydro Hot and that should keep the coach interior toasty plus prevent freezing in the wet bay.
