Coming from the Cleveland area, I know that tree. I also know others in the area that are kept outside over winter. Nearly all of them are covered. My friend in Cleveland Heights has had hers for as long as the one in the article. Others, in the Little Italy area, are uncovered and survive winters with the heat sink of the city.
P.S. I know all the folks mentioned in the article! I'm in NY now. Interesting to see the names in print.