Joe, I "bare Root" mine! If you keep them potted and they have moisture and not enough light or heat they could
ROT. They don't have to be in the dark to go Dormant. I bare rooted several last year,trimmed off the leaves,then put the root ball in a plastic shopping bag and put them in my outside bldg. luckily it didn't get below 32 in the bldg.. Didn't loose a single one.
I believe your Banana Plants will go Dormant in your basement, regardless of the temps of 55 or 60, stick the root ball in a plastic "walmart bag" .... bare root them and keep them dry.
Good Luck,
Frank