Think "dry" camping. NO water will be available, system should be winterized unless one plans on spending a LOT of $$ of ele and gas for keeping the thing up to temp... and then when one is dragging it from place to place????
Setting up a secondary Tank with RV anti freeze for the toilet or get a portable pooper.
We keep a couple of gallons of drinking water in the cooler in attempts to keep it and other foods from freezing.
Placing the batteries INSIDE the heated area with venting to the outside is huge for keeping our T-105 lasting longer. Built a compartment that is uninsulated to the living space against an exterior wall that is insulated. A piece of rubber inner tube was used as a 1 wayish valve(like on the top of a snorkel) and was zip tied to the vent, air flows out ward better than inwards.
Make sure you have something to place under the pads of anything conductive touching the ground, it will melt into ice. leveling/ stabilizing jacks, tung jack, metal stairs, etc... damn near ripped the stabilizer feet off on an RV camping Whistler/ Blackholm parking lots. Ended up pulling cotter pins, raising hydraulics, driving off feet/pads, then using a hammer and tire iron to remove all 4 from under inches of ice.
IF you aren't using shore power to keep the heat up, using a generator gets old.... bulking up batteries and solar is great but one would have to almost double up # of batts for zero temps as they don't put out well in the cold.
If your bed is against an exterior wall or on tire wells adding a layer of insulation between the mattress and the "exterior" portion will cut down on the amount of moisture the mattress picks up.
Using some of the plastic window kits from a hardware store really helps the R value on windows. We actually use the foil faced bubble wrap for both black out conditions and heat retainment. Plugging up all vents but the one that is kept cracked helps a ton too, Reefer and stove vents suck a lot of heat, IF not using them block them up for the season, keep the refer heat for sure, not the exhaust gas :)
***BEST thing purchased for winter camping...12V heated mattress cover, get it up to temp 15-20 min prior to getting into bed (#5/6 out of 10) then as one gets into the sack turn down (#1or2 out of 10)They don't draw enough to worry about for the heat they give.
My wife liked it so much camping we now have one on the bed at home.****
There are a few really good tricks in the truck camper side of the house.
Sorry for writing a book
Repo