Originally Posted by
tomusan
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Any thoughts/experience along these lines would be very much appreciated.
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.
US land border requires valid passport, passport card, Nexus/GE Card, or EDL (passport card/drivers license combo issued by some border states) since 2009, at least in theory; it's not like it used to be when birth certificate and DL did the job. The advantage of crossing at a land border over airport preclearance is that he technically can't be denied entry since he's already on US soil; CBP can, however, make his life miserable for not complying with current documentation requirements.
In his situation I'd probably still go land border over flying if the trip were life-and-death, but given a choice I'd skip the trip entirely.