Fate of an avocato tree in Michigan weather.
Kalamazoo County Michigan
No personal experience but, I have a friend who regularly keeps one as a houseplant. She just keeps pruning it to size. Once it gets too leggy, she starts a new plant from seed, about every 4-5 years.
Based on the hardiness zone of 9-10, no, the plant does not have a chance to survive winter in Michigan.
The tree can go outside for the summer. They are hardy to about 40-45F degrees. References list it as USDA Hardiness zones 9-10, so the variety varies somewhat..
Here are a couple references with some pruning information, and one on how to bring plants in for the winter. Remember to treat it as a houseplant, gradually getting it accustomed to outdoors by hardening it off in late spring, then bringing it indoors in fall when nights dip below 50F.