Welcome the Org mtilton!
You should be able to grow Dwarf Cav. in the ground during the summer but will need to pot it for the winter, or you can just grow them in big pots and move the pots inside for the cold months. There are several members that dig their plants up in the fall and replant in the spring. All of my plants are in pots as I'm in zone 4b-5a, right on the edge. This past winter was my second year overwintering and didn't work quite as well as I thought it would, (couldn't control the humidity in the room where the plants were). Killed off two Bajoos two Ensetes a siam ruby and my lasiocarpa, strange, but the more delicate plants, Gran Nain and Dwarf cav. survived, alittle ruffed up but survived, and I'm looking forward to the warm weather staying around for a while so they can recover and start growing like crazy again.
Time to put the bananas to sleep for the Winter is a good thread to start with for a search of info on this subject matter. Best Wishes
Bill