It's late for planting now, but I would think that it would be safer in the ground than in a pot. Just plant it so the crown is like 6 inches down and keep it watered well until the ground freezes, and put a good thick layer of mulch on it after you plant it too.
Others may have other opinions but that's what I would probably do myself.

Oh, and absolutely NO fertilizers now. Wait until spring for that! :)

The last 2 years I have found large pots of clems at a bargain price in November. I dug holes near the foundation, sunk the entire pots in the ground, put a green chicken wire around & filled the wire circle with about 12" of chopped leaves. All 5 I have done this way grew in the spring. Then I pulled up the pots & planted in their permanent location. Felt it was to cold too plant in Nov here in NE Iowa.
Good luck!