Flight tomorrow BOG>MAD IB6590 at 14:10, for 4 pax booked into J using cash (at a good price), booking made last June.

Did OLCI this morning, and all our boarding passes are showing SBY-STL and Group 4, which makes me think they have oversold, and potentially we have been selected to go on the waitlist?

Have never been in this situation before, so just asking what should we do, if anything?

There are 2 flights later the same day which seem to have more space, and it wouldn't be the end of the world if we took them (we have a connection after to PMI, but that should be an easy reschedule).

What we wouldn't be happy with is:
1 - Being downgraded, although that seems unlikely as Y and PE also seem full/oversold.
2 - Being split up onto separate flights, both for the enjoyment of flying together, but also the final journey by car from PMI to home.

Any advice greatly appreciated,
Thanks!