Wish I had seen this post earlier. I had our Montana HC in Tulsa last January. Temps down around 15F most nights. I turned on all storage bay lights and put 2 drop/trouble lights in the bay. I discovered the hot and cold lines going to the washer/dryer prep were right up against the exterior wall on the curb side. Looked like an excellent spot if you wanted to freeze them. I slipped some foam pipe insulation over them.
I used an electric blanket on the bed, kept the fireplace on, and set the furnace so it would run occasionally overnight. I disconnected the water hose on both ends before sundown. I stayed comfortable and had no problems.
Let us know how your experience went.