Originally Posted by Elk Dawg
... but this next week or so is going to have overnight lows between 32-28 degrees. ...
Your system will not freeze immediately at those temperatures.
As I have stated in another post, the thermal mass of the trailer alone is your friend.
Do a quick search on the process of water freezing (changing state).
Water does freeze at 32F. It doesn't happen immediately. Changing water to ice takes more than just an ambient temperature of 32F. The heat energy in the thermal mass needs to go away enough for the water to change from liquid to solid. Change takes energy. Water will circulate as temperature changes. At the temperatures mentioned above freezing will not happen to a trailer water system overnight.