Here is what has worked for us.
at about 0 degrees the main water line from the pump to the kitchen/water heater would freeze. I installed a computer fan that now directs heat to the area, no more problems. Our tanks are heated.
We have been in temperatures to 15 below. At 15 below we call it quits. Its not worth it and at at temperature below 10 below our propane regulator freezes and the game is over we go to a motel or home, whichever is closer. Yes, we have cold weather gear but its emergency use only.
As long as we have propane, which in 0 degree weather our 30# tank lasts 3 days, all systems are operating as they should. I carry a spare 5# tank. If our furnace malfunctions, I carry RV anti freeze that I would pump into the system, drain the water tanks and the holding tanks asap with RV antifreeze. If you cannot find any other place to dump, virtually all waste water treatment plants have an disposal dump that RV's can use.
I think the idea of trying out your camper at home is a good one.
Good luck.
