mockturtle wrote:
We never had a freezing problem in Yuma. If you expect sub-freezing temps overnight, just disconnect the water hose. You can also open the lower interior compartments to bring heat to the water lines.
What we do on the Olympic Peninsula in WA - in the winter - is to leave the gray (or galley) tank valve open, and on the freezing nights run the water in the sink at a trickle. Running water can keep the spigot and water line from freezing - even around 28 degrees F.
This works because the days are well above freezing. I have an Oregon Scientific indoor/outdoor thermometer that has a Freeze Alert. At 37.5 degrees F a very annoying green LED starts flashing. That reminds me to run the water. Also the park usually informs the campers on the very cold nights to run their water - because they still have to go around to the open sites to crack the spigots open.
I talked about wintering in 2011-2012
here at Travel Inn RV Resort in Elma, WA.