Ok....we're talking about the same thing, let's try not to confuse the OP.
You don't have to be hooked up to municipal water....they can just fill their fresh water tanks, which is what most do when freezing temps are expected. Then you don't have to worry about your hose, connection, etc.
Might be able to wrap that external shower....its behind a door, so somewhat protected.
The moderator pump is a different story.
My references were to the interior staying warm enough, with the furnace running at comfort level, to keep things from freezing inside.
I've realized the municipal connection you are talking about is the campgrounds, not the connection to it from the Interstate.
I've never heard of anyone carrying something to protect the campground water supply, but one could certainly do that if the campground didn't take care of it, I guess.