We have been down to -3 so far this winter waiting for DW Chemo treatments (only one more) before we leave MI and head south. The 100W & 75W light bulbs are no longer available but I'm using 60W without a problem. As long as temperatures do not go below 25 for a long period your water hose should be fine. I've been doing the tank fill and only dump the sewer when needed.
I have a 30# and the grill 20# tanks and using the extended stay on the MH. The 30# will last about 5 to 7 days with night time temperature below freezing. It's good to have a electric ceramic heater on hand. We use vent pillows to block the vents when not using the fans and when showing open the vent and run the fan to cut down on condensation. This was the biggest thing we have had to overcome is keeping the moisture down. Another item the DW found that helps is she has the front curtains closed and a sheet hanging from the overhead console to the floor which blocks a lot of the cold air from the front windshield and floor area. I also block the lower vent on the outside cover to the fridge and have a 60W bulb in a drop light in there when it's below freezing since I have an ice maker and to protect the gas mixture from gelling also do a search on fridge operation in freezing weather or winter camping there are pages of good information!