Water in winter

My coach is all basement heated so I don't have to worry about that! There have been posters in the past that said just using a string of Christmas lights around there tanks was enough to stop them from freezing!

one of my bays has a 100 gallon water tank and the bay next to it has a large opening with the 65 gallon black and 65 gallon grey tanks. I plug a small 120 volt heater into one of the temperature activated plugs which activate the heater when the temp in the bays gets down to 35 degrees. I have been in temps down to 10 degrees for 2/3 days and never had any freezing problems.It doesn't matter whether I am plugged in or on the generator. If I am plugged into a campground using pole power then I run a separate power line from the pole power stanchion to reduce the load in the RV because I run other 1,500 watt heaters.

I flush with windshield washer fluid, much cheaper than rv antifreeze

I can only speak of my experience in cold country. I winterize when the temp drops below 10 degrees while on the road. I blow out my lines with a portable air compressor and drain all tanks. I use RV antifreeze to flush toilet and bottled water to wash and cook with. As water goes into grey tank I add RV antifreeze although I realize tanks are heated and I am reasonably safe. Blowing out lines only takes a few min. Since I don't use pink stuff I can dewinterize within minutes. You just have to be flexible and act accordingly. I have a temp monitor in my wet bay. However, my ice maker line is out in the open. Just look at your RV and decide what may be a problem in freezing weather.

12v tank heaters??