We winter camp in the area quite often and we also had a trailer parked at our farm (southern VA) for a while. A few things we learned:
The wind can be a lot worse than the nightly drop in temperature. Try to park in a less windy area or one that has wind breaks (trees and bushes) on the side of prevailing winds. If you aren't moving the trailer for the entire winter, skirt it.
Sunlight heats up a trailer fast. Don't park where it is shady.
Heat tape and insulation (the gray pipe shaped stuff) are great for exposed pipes and hoses.
In 13 winters with the trailer at the farm and two winters camping, we only had freeze problems twice: our fresh water tank once when wind got under the trailer (it was about 1/6 full) during a snowstorm and once when we didn't unhook our hose overnight (no heat tape or insulation). Both situations were resolved about two hours after the sun came up with no damage.
