We take ours out at least once a winter for "go south, get warm" trips.
I often just connect to city water at the 1st place we stop.
After making sure my anode/drain plug is back in my water heater and
bypass valves are all in summer mode I flush the lines and make sure
the water heater is full and we're ready.
We use filtered city water out of a blue jug for a couple of days for drinking
but wash dishes and shower normally. After a couple days we just flush
the line a minute before making coffee or filling water bottles.
If you're using your fresh water holding tank and on board water pump
you need to sanitize the tank at least the first time you use it.
Or don't sanitize it and just use blue jug as above until you can sanitize it
later..... Don't make this harder than it needs to be!