Burl, I dewinterized our rig for our dash to Pensacola last month and rewinterized it when we got close to home and the overnight temps dropped well below 32. I read the system will be okay if the night time temps do not get more than a couple degrees below freezing and the daytime temps are above freezing. It was that way on our return stops in KY and WV. I filled the lines back up with two gallons of RV antifreeze when the teens and twenties were predicted New Years day in WV. I noticed that both hot and cold lines are cvpc. Since it is the only plastic pipe rated for hot water perhaps it is stronger and can resist a bit of freezing. I have not had a problem in delaying winterization and using the rig in low thirties here in VA.