This comment is regarding winterizing.
In previous years I would pull the return water line from the fill cap and pump the water back into a distilled water bottle.
This year I hung a small light bulb of about 15 or 20 watts next to the water tank. I used an extension cord and was carefull that the bulb did not come in contact with the plastic tank. It seems to work and I only used it when the temp was forcast to get down into the 20's.
2011 Ford Edge