I am flying on CO (SAN-IAH-ORD) with my wife and son. We are booked on same itinnerary with my NW Gold WP#. We have great seats in coach.

If I get my name on a separate itinnerary for any chance for First class, they would get boarding in some zone 5 or so... Can they board when I board? Also, are NW Elite upgraded on their own, or they have to do buttering at the gate?