Hmmmm,
Some of us used our rigs year around as ski huts, snow mobile huts.....temps from 0F to mid 40s in the cascades depending upon the early December to early April time frame.
I kept the trailer at my house, cold temps, ie below 32F 24-7 had the LP going. I also set it to about 45-50 during the week when we had typical Seattle days in the 28-50F relm.
THE biggest issue I had, was a manual drain valve, the water would freeze up into the to main part of the trailer. Then the water was shut off from the water tank to rear bathroom, front kitchen was fine. Our water heater was also in the back, so no hot water. Took out the drain lines, no issues after that.
Reality, until you try it out, you will never know what will or will not freeze up. As long as you keep some heat on during the below 32F 24-7. You should not have issues overall.
Marty