If the weather stays below freezing for 24>36 hrs, I would consider running the furnace, draining the fresh tank, and opening the low point drains on the hot and cold lines and all the taps. Run the 12v waterpump tll it sucks air. then you'll realy be fine, but for a short freeze I wouldn't bother with any RV A/F.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.