Are you by chance growing musa basjoo in zone 5. Maybe that one can stay outside in the ground if well mulched?

You're not totally off base, I've been debating the same thing for my bananas. For me it's either grow them as a houseplant over winter (water sparingly and be prepared for them to look "roughed up" by spring) or else try to store them in a dark but fairly warm basement. Unfortunately I really don't have a cool dark basement. Especially with a dehumidifier going which may reduce humidity in the air, but also seems to warm the basement even more. Regarding the fridge, maybe the humidity and lack of air circulation might be a problem in a fridge though, as you point out. In theory though, as long as the fridge doesn't go below freezing, one might be able to store all sorts of bulbs in there. Maybe be careful to wrap the corm in paper versus plastic, which holds humidity and can rot the root?

This could be an interesting winter as I have a four foot high musa basjoo which I have to dig up and either store the root the way people do or else pot up and grow in a sunny window. Either way, I'd really hate to lose this plant. It went from a seedling to four feet tall in one growing season. Next year if it survives it may be even more impressive.

Regards,
Glen
(wishing he were a few zones warmer or had a greenhouse).