If you are on hookups, I don't run my propane furnaces during the day; I use electric space heaters....saves on propane refills and $$. My rig has three separate heater vents going to the holding tank and storage bay areas, so running my propane furnace at night keeps these from freezing. The bay doors also have about 1 1/2 inches of styrofoam insulation, which helps.
I also open all my under-sink cabinets at night to let heat in there to keep those pipes from freezing.
Last year, my ice-maker valve froze and cracked spilling water everywhere under the fridge when it thawed out. I now turn off the water to the ice-maker and disconnect the line to the valve to bleed off the water inside, then reconnect. I only do this if the temps will dip below 20 deg F.