Jim,
I know you live a bit north of us, but we don't winterize when we get back. We drain the water. Most nights it does not get below freezing for more than a couple of hours, it has been our experience that we will not freeze up in a couple of hours.
IF we see numbers low enough to concern us (probably below 25 for more than 2 to 4 hours), then we can always turn the heat on 45 for the night and that handles that.
Course, we are rather lazy! Don't want to spend the energy and time to winterize unless we really gotta!
Safe rides back!