I can't specifically answer your querie, wod, but it seems to me that anyone who ever even thinks
they might one day leave their home country should obtain, and carry, a passport.
Unless a person has some overwhelming reason not
to get a passport (I can't think of such a reason), why not get it, carry it, and always protect it. It's rock-solid ID, and if you've ever decided at the last second to travel somewhere, forget doing so if that somewhere is outside the country, even to Canada
The days when just being an American meant the rest of the world welcomed your visit (and your cash) are long gone.