The safest thing to do would be to skip the trip. The next best would be to fly to the nearest US/Canada border city to your destination in Canada. Then rent a car. The land border requirements are easier to deal with and the pressure is lower than when you are trying to get a flight back into the US and have to deal with pre-clearance ahead of a flight. The delay could be quite long and you could miss the flight or the airline might not accept your documents. At the land border you need proof of citizenship but not a passport.