[Dick D]

Terry,
I fill my fresh water tank and drain & store the hose. Normally we will have 3 or 4 cold days and then it will go above freezing, so I drain & refill. I do use a trouble light with a 75 watt bulb in the belly behind the storage and keep the doors closed between storage and belly. I also use a remote reading thermometer in the belly to keep up with things down there.

When it gets really cold, you do want your furnace to run so it will heat the belly and keep the pipes and tanks from freezing.
I've gone to -6 F. using this system and it was that cold for several days before I could get out of here, and find someplace warm. Don't intend to ever do that again, but the Suite kept us nice and warm without drafts