Gardening and Horticulture - patio peach tree

Hello. I have a patio peach tree bonanza that i purchased this spring for my deck. The tree appears to be about four years old. I brought it home and transplanted it into a larger pot. I live in pennsylvania. The winters up here can get pretty cold sometimes. My question is where do i put the tree come winter? If it was in the ground i would be ok as the tree is hardy up to -20. If i leave it on my deck in the pot it would freeze wouldn't it? I do have a small porch room in my house that has no heat. It gets pretty cold out there but never below freezing but at the same time it can get warm in that room if it is a nice enough day out in the winter. I would really like to keep it in the pot if at all possible cause the darn rabbits will eat it if not. Any suggestions?

Why not plant your tree in the ground and just put some hardware cloth around the base as a trunk protector? This one has a chain link fence, by you get the idea.
http://upload.wikimedia.org/wikipedia/en/thumb/9/9f/Devil's_Tree_protection.jpg/250px-Devil's_Tree_protection.jpg

Newt