About what I expect. I also have a couple of lampholders to put in each of the bins that have water, with 60 watt bulbs. Last time were in cold, I put a remote thermometer in the bins so I could keep a check. With the bins closed, in outside temps down into the 20s, the bins held well in the upper 40s. I will probably wrap the water hose, and may use a heat tape, but always disconnect it below freezing. Underbelly does have heat vents into it, but we use electric heat a lot, so the furnace doesn't put much deat into the bins. Hadn't thought about the dehumidifer, but sounds like a good idea.