If I know it is going to get below freezing here in Wyoming and I have water in my system, I have a $20 dollar Wally World electric heater that I set at 60 degrees and let it run all night. I have my camper plugged into my 30 amp outlet at my house and then I open up my access door inside to my water tank so air circulates throughout my camper. I also have a non-LED light in my drain bay and sometimes I will turn it on all night because it does put off just enough heat to keep it warm enough to not freeze. I will typically not run my camper heater in this scenario.
When I first got my camper I was worried about those times during late fall and early spring where it warms up above freezing during the day and then dips below freezing at night. I asked my camper dealer about it and what I stated above is what he told me to do.
2017 F350 Super Duty 4x4, CCSB, XLT Premium Package, 6.2 gas, 3.73 rear end, GVWR 11,300 lbs, Payload 4226 lbs, Silver Ingot, Camper Package, Split bench front seat, Upfitter switches, LED Box Lighting, Rear Step Tailgate, Air Lift 5000 Ultimate Airbags with Air Lift WirelessAIR on board compressor kit and remote, Torklift Upper Stableloads, Torklift tie downs w/ Fastguns
2017 Northern Lite 8.11 QC SE