Sounds like your mrs doesn't understand the importance of di vessels that work.
Think you need to explain the pure water system to her, how it works and what happens if you can't run water through the vessels.
I wouldn't say that they need to be in front of the fire though. Just in a warm room close to a radiator does the trick when my reel and everything else has frozen up.
Suppose I'm quite lucky really. When the weather gets to 0 or below I have my kit in the house and my wife doesn't bat an eye lid
100m hosereel and 3 poles in the bath
Transfer hose, pump, connecting hose, batterys, cloths in the kitchen
My RO runs out of the office.