Yes, I am worried about the pool plastic, your situation sounds a lot better Cecil because you will have insulated building and the passive solar, mine is not insulated, my south central Wisconsin winter might be a little colder than north eastern Indiana but probably close to the same. I have read about people leaving their intex pools set up over the winter, but most of them are in southern or middle states. I think testing it would be good, but we need an exit strategy if the plastic cracks so we don't have 1k gallons of cold water flooding our building in the middle of winter, hehehe.
