I have a 35'11"long 2006 Carriage. I have camped in 15 degree weather at night. I use the furnace to warm the 5th wheel up quick when we get there. Then I have 3 electric heaters to keep the 5th wheel warm. I keep the cabinet doors under the kitchen sink and bathroom sink open so the heat can get in. In the front storage where the water tank and lines are. I mounted a 110 volt single bulb white fixture with a pull on and off chain. I have a good supply of the old type 60watt bulbs that put out heat. I turn on that single 60 watt bulb and it keeps the compartment above freezing. The first night I unhooked the water hose and rolled it up. But on the second night I said why not do it like at home. I didn't need to run the hot water because of being inclosed in the RV. I just ran the cold water in the kitchen sink at night. And did not have a problem at 15 degrees with the water hose freezing. This way with the electric heaters I am not burning up all the propane like the rest of the RVs were at the campground.