Traveling in the Cold

DW & I used to camp every other winter weekend in MI often driving up to the UP. Temps were always below freezing and often well below zero. We'd carry our fresh water in clean milk jugs kept on the floor in the shower. I used automotive anti freeze in the black and grey holding tanks and when dumping was needed, the tanks and valves were not frozen. We probably did this for 10 yrs with no apparent adverse effects to rubber seals etc. Then the MH was stolen and whether the "new owners" had any problem or not, I do not know.:) FWIW