I cut mine off at the ground, and have about 2 feet of mulch on top of the base. From what I have read that is the best for the colder areas. Hoping they come back. I have 6 total, so we'll see in the spring.
Have you winterized your banana plants yet? I think we will get to ours this weekend. After doing research - I plan to straw up the base - there is a wire cage around it to keep our pet rabbits from eating it - and fill that up. I'm undecided if I should cut the leaves?