I'm not even opposed to that. The NAU has been predicted for a long time, and seems inevitable to me. And you probably could keep your health care. Health care is primarily done state-by-state in the U.S. The Obamacare thing is just to pay for insurance, which you wouldn't need. And as I said elsewhere, probably noplace in the world are there two countries whose ethnicities, languages, borders, governmental systems, and cultures would dovetail as smoothly as Canada and the U.S.
Should probably try for at least two states, though. Ya get more senators that way. I could see the Maritimes, Kay-beck, Ontario, the Prairie State, and BC.