This tree is a push for me, but I’m going to give it a go. You growers in town? I think you’ll be ok. This evergreen magnolia has apparently easily survived -27, and mostly survived -33. Out here in rural La Farge we haven’t gotten colder than that in a couple of years, so I’ve already forgotten that it can.

If you have great luck, expect it to get 40′ or so tall and about 15′ wide.