Originally Posted by
ESpen36
Just a thought: I always carry my passport book, passport card, and NEXUS card when traveling. You just never know if you might have to reroute via a third country or decide to take a spontaneous trip overseas! Better to be safe than sorry.
This. It will also help during IRROPS. I've seen people going to NYC/MIA/etc routed through Canada because it was the only available option.
Plus in extreme situations it helps too.