You can definitely register her as a Canadian boat... probably more easily done and less complicated than trying to register in a state as a non resident.
You need not ever actually import the boat into Canada, but if you do that's when any taxes and duties will come to bear.
Leaving the Canadian registered boat in the states may be a further complication.... and that's probably on a state-by-state basis.. (Here out west plenty of Canadian boats are moored in WA state)`
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
1984 Fast/Nicholson 345 "FastForward"