I grow all of my bananas in containers - makes transportation a little easier lol. I left them in the containers last fall and brought them into the basement for the winter (50-60 degrees F) - all of them went dormant but the psuedostems remained green all winter. My 14 foot mystery banana plant, well, unfortunately i had to cut pseudostem to 4 feet to get it into the house - lol, but even that one sprouted leaves again when i took it out back last MAY. I covered the plants with a loose dark plastic bag and gave each banana about a cup of water a month to keep the corm and soil lightly moist (no fertilizer since they weren't growing).
All are still alive and happy as a clam - er, naner.
But that's my experience with bananas so far. Search the site for more info and recommendations on overwintering to help you form a strategy for your banana corms.