DrewE wrote:
Where is the fresh water tank?
If it's inside the insulated envelope of the RV (underneath the bed or dinette, say), then it'll absolutely be fine; the interior of the RV will likely not even get below freezing, unless you leave windows open or something, and much less the water in the tank. If it's exposed outside, it most likely would be fine, but since draining it is (presumably) not much work at all, I'd likely do that just because.
It is in the frame somewhere near over the rear axle. The 5er has a covered bottom. The drain is just a 1/4 turn valve. Not exactly sure how much water is in the tank, best guess between 10 and 15 gallons. It didn't freeze last year but we were living in it when temp was in the low 20's a few nights