and, as for the 'fresh water tank'....BULK water takes even LONGER at much lower than freezing temps to ever get to any place that you should then be concerned about, if at all. I would not drain the whole fresh water tank simply because of some freezing temps, even if over several days. Don't fret it.
And remember that, most likely, your Class A is like most all others - all of your water lines and holding tanks are contained WITHIN the RV, not exposed to the elements, wind, or direct temperatures from outside.
Other RVs, though, like my son's camper, is a different story. His holding tanks are all under the trailer's flooring, in the direct temperature and elements. Even his holding tank drains are all exposed. I used a 'construction bag' from HD to craft a 'heating tent' under his trailer to keep the extreme lows from potentially creating any issues since he is parked for the winter and living in the trailer while at UAH for Aerospace engineering in Huntsville, very north Alabama.
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