The Mpemba effect. Interesting phenomena but did you know that water can boil and freeze at the same time? It's called the triple point when under the right conditions, water is in a gaseous, liquid and solid form simultaneously. Simple (not) explanation
here.Seems to me that when and if the WH goes out depends on where it is. It only has to go out once while in transit and you could arrive at the destination to find everything frozen solid and then damage to fix?
I'd be investigating other options, if there are any. Maybe purge the lines and HW heater each time and come up with a way to prevent just the tank from freezing? Maybe if the water is sloshing around it won't freeze at a few degrees below zero like when you let an outside faucet drip/dribble? How long exposed to sub-freezing temps and how much below freezing?
