[JRTJH]

The two most vulnerable spots for freeze damage are the city water inlet/hose and the terminal sewer connection. If you protect the city water connection and hose with a heat tape, or on nights when the forecast calls for freezing, simply disconnect the hose, drain it and use the fresh water supply in the trailer, you can prevent most "frozen clean water problems"... As for the sewer connection, if it's freezing, then the "slow trickle" of waste water is a "sure way to freeze and block the sewer hose. The easiest way to prevent problems is to close the dump valves (yes, all of them) and only empty the tanks when they are full. That way, the sewer hose stays empty and although it will be "cold, rigid and hard to coil" it will be "dry inside and not plugged with ice (frozen black or gray tank effluent)...

Although most of us don't travel with the furnace turned on, remember that there is no heat "below the floor/above the Coroplast" unless you run the furnace. The heat ducts run through that space and they do make a significant difference in keeping things "under the floor" from freezing. Using an electric heater in the cabin does nothing for things that are under the floor, so on "especially cold nights" be sure to run the furnace, even though the fan kicking on every few minutes does keep you awake, at least until you get used to it..... YMMV.