Good point, however, your freezer was already working and not really that much of an additional cost to freeze a few water bottles(tank size of course will dictate this).
Anyway, I do agree with it being a pain in the butt to use frozen bottles, but they do work in a pinch.
I just wish I could find a way to NOT need a dehumidifier in my partially finished basement in the spring/summer. My power bill goes up from $150 to $300+, and that's with me having shut down 3 tanks out of 6 in the basement this year in hopes of it helping keep humidity lower.
If I DON'T use one the humidity jumps from a tolerable 50% to 70-80% percent very quickly(which is quickly followed by moldy smell, then actual mold), especially when we have rain like we've had all week, and then sun, then rain, etc, etc