Just a thought - unless you are planning on camping in really cold weather, a large tank full of water will not freeze enough to do damage at or above 30 degrees or so. The pipes will freeze, but that much concentrated water takes a while and some very low temps to freeze hard and expand. JMHO
2003 Ford F-350 V-10 Crew Cab 4WD Long Bed
2004 Jayco Designer Medallion 29 RLTS 5th wheel
Bill, Gayle, and Mindi (dachshund)
Retired at last !
Nothing is foolproof to a sufficiently talented fool.