Here is an interesting article on the Maine Coon Cat. It certainly supports the idea that Vikings brought some of the original breeding stock. Perhaps it went wild and then mated with cats brought by early New England/Canadian settlers. The fact that it has a gentle good natured disposition makes sense. Can you image several months at sea with a cranky, restless cat? Might get thrown overboard by those “good natured” Vikings.
http://www.unm.edu/~njmoore/MainCoonHistory/History.htm