[JRTJH]

I live in the "tundra" in northern Michigan, regularly get -20F temps for weeks on end. I flush and drain the tanks as a part of winterization. Run antifreeze through the hot/cold lines, then park the trailer in our pole barn. Once parked, I open all the faucets, put a 5 gallon bucket under the dump opening and open all the valves. After a couple of days, I remove the bucket as there's nothing else to drip out. I leave the valves open, that way if anything should still be in the tanks, even if it migrates to the valves, it can't freeze and expand.

Come spring, I drag the trailer out of the pole barn let it sit in the sun for a day or two, then close the valves, flush the antifreeze out of the lines, sanitize the fresh water system, check everything for leaks and we head north to do some fishing.