We have been out several times in weather below freezing. Biggest problem is the condensation that builds up. We keep the Bathroom fan on low and also crack a window to get air moving inside the camper. We do not fill the Fresh Water Tank but carry cooking and drinking water with us if the camp does not have fresh water. The heater that comes with the camper does a great job keeping up even when temps were about 5 degrees and we had 2 foot of snow. (That time we had to come back for the camper as we could not get it out.) I do try to get at least a electric hook up during the winter but some camps are totally shut down.
Towing the camper on snow and ice is even more fun as the camper WILL slide around. Take it slow and you will be ok and look ahead or plan ahead before taking the camper with you. Are there big hills and curves you have travel that are still covered in snow? Is the camp ground going to be plowed so you can get in and is the camp site going to be plowed or able to get in.
We did more winter camper than we did camping this summer due to work schedules and looks like I will be doing a lot between December and Early March.