I've had good results most years planting in-ground under the eaves on the protected side of the house. However, you have to pay close attention to moisture needs during the winter. The other way that has worked was to dig up the plant, replant in a large black nursery pot, place that pot inside another pot (or garbage can) surrounded by bark on the sides for insulatory purposes. Site this under the eaves, and protect with a layer of row-cover. Again, the roots need to be kept moist during the winter.
A friend of mine used to wrap her bananas with a blanket then surround with bubble wrap - looked other-worldly, but worked well.
Moisture is the enemy. Sometimes you can avoid crown/root rot by amending the planting hole with pumice or granite chips, particularly around the crown, which I tend to plant slightly above the soil line. The plant may top-kill, but the roots live & the plant rebounds the following spring. Our problem here tends to be freeze/thaw related, splitting the trunk or stems.
