We have some freeze proof heated hydrants in our late season section. Its for our protection, not yours. A heated hose is worthless unless the supply faucet is also freeze proof heated.
By far the best idea is to fill your fresh water tank, disconnect then use your pump. Its so minor a proactive issue. Then you do not need a heated hose, no concern of a frozen hose when you use your tank and pump.
be wary. --- no run away, of those who say 'trickling ' water during cold spells will get you through. That very slow trickle will freeze in your waste hose, turning it into a 3" poopsickle, which will back up into your rig and flood it. Do not trickle the water.
Ask camp management about their water supply, They know their system, and about your unit.