Here's a link on how to protect your bananas in the winter:

https://www.crfg.org/pubs/ff/banana.html

I think it would be tough to keep it outdoor with your Winter temperature there. Some people overwinter their bananas by cutting them down and then storing the rhizome indoors. When the warm weather returns, they bring them out to plant again. Here's a video link to show how it's done.

https://www.youtube.com/watch?v=ZVga_4pX0Oc

I know it must be disappointing to hear this .... I wish too they could stay out without being cut down. If you grow them in a greenhouse, that might be possible. Do you have a pool screen enclosure? If you do, I wonder if that could offer some protection to your bananas and if you could also warm the area up?

No, unless it is musa basjoo, in which case, it would be difficult but possible.

Violetz I have Musa Basjoo that stay out year round, but as far as I know those are about the only ones that would be hardy for us cold zoners. There are some great over wintering tips on bananas dot org that you may find helpful.

I live in Indianapolis..my neighbor has lots of bananas in the ground..she gave me one spring 2015..it lived!..we cut them back in the fall and cover for the winter..I filled garbage bags with leaves..laid them over the area and laid a branch on top to keep them in place..a pic of a couple of my neighbor's..mine is still small - 3 to 4 ft..