Greetings from balmy Massachusetts. I've got six Musa Basjoos that I used to treat as you presently are doing. Right now they are in the ground and well mulched. Leave the pups alone and water it when the soil gets dry. After you put them outside in the spring then separate the pups.

I'm not sure what you have left after you moved them. Normally you do not want to separate smaller pups in the fall. Real big bananas can be seperated when bringing them indoors to overwinter. I always have to do this with my cavendishes; otherwise, I would need a forklift just to move them. Keeping a banana in a garage in Michigan is not good...as you learned. At this point, unless you had access to a greenhouse, I would not do any seperating until this spring - assuming you still have something to separate. You might. I supose you could take a peak. I know I have been surprised before. You might consider buying an additional musa basjoo this spring and planting it permanently.