At Trailer Village with full hookups and an RV with heated tanks/ underbelly/ basement - you should be fine if the temps stay average.
It really depends upon how your specific rig is built for winter. I would not plan to use heat tape/ wrappings on the fresh water input there. Fill the onboard tank about 1/2 to 3/4 full in the afternoon, and disconnect and drain the water hose. Actually, I'd suggest you call Xanterra and ask them if the water at each campsite will be on during freezing weather. You might have to fill from a centrally located 'frost free' faucet.
Don't leave the grey water open at night. Dump it when it warms to near freezing if you need to.
