Even if you sanitize in the fall, if the fresh water system sits unused for 3 months, it will have to be re-sanitized when they go to use it.
If antifreeze was used to protect the system, the whole system will have to be flushed. Then sanitized.
If the lines were blown out, the whole system will have to be sanitized.
No gains to be had.
TT 2015 19RD "TheJayco"
TV 2003 F-350 "Montblanc" - Housebroken chore truck
Sitting in The Cheap Seats.
And proud of it!