Mine stay at room temperature all winter....about 65 degrees. They also have weak flourescent light about 16 hours a day. It's not enough to grow them under, but I think it helps a bit. If you have access to a warehouse that stays relatively warm, i think you'll be succesful with them.......BUT...........they won't look good in the spring...........but will recover well with heat and light. Good luck!
Yeah, I could always just put them in my greenhouse that I set up for my tropicals. I did that last year, but the only problem is that the banana grew so ridiculously huge during the winter that it was hard to walk in there.