I booked my wife and I on an upcoming shuttle trip (DCA-BOS). Turns out that I need to be in Boston earlier in the day, so I'd like to go standby (is it still free if you don't do confirmed, by the way?) while she takes the original flight. Do you envision this being a problem? Should I call reservations to split the reservation before day of travel, or should I just show up at the airport and take care of it there?

Thanks!