Catman,
I do the whole "WorkAmping" thing. (Work/Camping). Have been doing this for ten years now. Did a stint in Tioga, ND and Chicago, IL during the winters.
I have learned a few tricks that help. I too served 15 yrs active. (I was "Right-sized")
Water supply- Pex tubing with pipe heaters wrapped around it, then 1" thick insulation around that. Keep water in the line! Ensure heat elements have a functional thermostat.
Bury the water line as much as possible- If this is allowed where you are at.
PVC piped the waste piping to the Septic.
I hung C33 christmas light strings under the trailer- then I slid bails of straw/hay under the 5th wheel around the whole perimeter. I used 6" PVC pipe through the bales to get access to my dump valves. Wrapped coat hangers around waste gate valve handles to use as extensions. 3' long 2" dowel rod to push handle back to closed position.
3/4" rigid foam skirted the trailer on the outside. The bales, rigid foam insulation, and the lights kept the ground from freezing under the RV. Lowest temperature seen in ND was -35. Had several days in a row of -20. All Fahrenheit readings.
2" rigid foam insulation around all of the slide outs.
I had the propane company bring out and hook up a 220 gallon tank to my RV. I used an average of 124 gallons every two and half weeks from Nov. to March. (ND)
Inside of RV never above 65 degrees except when cooking- Thermostat set for 80 degrees.
Open all cabinet doors to prevent ice from forming in cabinets. Dehumidifier is needed also.
If possible get a Mud Room Added in front of entry door. This helps alot also.
My tanks were heated. But I still needed to cut 2" rigid foam insulation to fit in the areas just inside my storage doors to help keep basement area a little warmer. I had remote temp gauges near my tanks to help monitor the temp and keep black and grey tanks from freezing.
I did not do all of this because I wanted to, it was out of necessity. It was pretty costly also, but then again, everything was and there was NO housing to be had in ND at that time.
When I went to the Chicago job I left off the C33 lights, the hay bales, and skirted with 1/2" foam insulation. I was there for 3 years. Propane use during the -10 degree week was about 55 gallons. I usually used just under 120 every 3 weeks. This was with the provider filling the 200 gal tank every two to three weeks during the cold months. Warm weather I used less than 7 gallons a month.
Electric in ND and Chicago averaged just over $200.00 USD a month averaged over the year.
None of this was cheap. I received per diem at these jobs. The per diem covered these additional expenses easily.
5th wheel is 10 yrs old now. Living yr round in these harsher conditions has taken a toll on it.
The Chicago winters were much easier than the ND winter that is for sure.
I am sure I have left out some of the tricks I used. I did all of this out of need and not out of desire.
The bonus was not living in crowded Apt. buildings and the potential for questionable neighbors sharing adjoining walls.
It can be done, it is just a matter of "is this what you want?"
If I was able to just be a "Snow Bird" then that would be fine with me.