I have a cutleaf maple in a large pot on my deck, it is about 20" in hight. Last year I had another smaller cutleaf in a smaller pot and kept it outside during the winter. I had a unusually cold winter (10 below 0 F. during a brief time) and the tree died. My question is will it be ok to bring the one I have now inside during the winter or does it need the cold winter to go into a normal dormant period to stay healthy? Thanks for any info.