If you have a 5th wheel you have a skirt made to go all the way around it. Purchase a heated water hose for your water hookup. In the up front storage I purchased at Amazon.com a programable outlet which I programed for 65 degrees. Plugged a heater into it so it would turn it on and off as needed. Put a wireless temperature monitor in the storage unit as well to monitor the temperature. Also put a wireless temperature monitor by the water hookup. Did not leave dump hose on all the time. Put it on once a week to dump then stored it. I also had a 100lb propane tank sitting on the outside so I did not have to move unit to replace propane.
We had 18 degree below tempuratures and had no problems freezing up. Everything stayed nice and toasty. With the skirt all the way around it also gave me a covered stoage area for the snow shovel, gas fire pit etc.
You just have to monitor things and you can RV all winter long. We had a friend who camped with us in is motor coach. The only thing different was he did not need a skirt.
It is important to block the wind from moving a lot under the unit. This year we are going to put some simple insulation sheets in the back of the cupboards because we seemed to get some cold from there.
It is fun RVing year round.