It's important that the tree dosen't get waterlogged, they do not like 'wet feet' It would be better to bring it in for it's first winter if you can but if you are going to leave it outside try and make sure that the water can drain easily from the bottom of the pot. If you are potting it on into a larger patio pot then put a layer of crocs (pieces of broken clay pots) into the bottom of the container so that the drainage holes do not block and preferably lift you container off of the floor slightly.