My dad smuggled a lemon tree from Italy back to the states. While it grew pretty large and the leaves definitely smelled like lemons, it only produced 1 or 2 lemons for the 8 or so years we had it. We live in North Jersey. If you want your tree to survive the winter, you need to prune it, then wrap insulation around the tree. Then you wrap plastic bags around it so when it rains/snows, it won't ruin the entire thing. Don't use black bags since they will absorb solar radiation very well and cook your plant, use white bags. Or you could just build a greenhouse.