I have a question for the loyal UA elites here:

My wife and I have a flight back from Buenos Aires to Houston on Nov 11 (2.5 weeks from now). I am a 1K member, she is a General Member. We booked our ticket a LONG time ago in April and applied our 2 GPUs (under my account to leverage the 1K status). I have spoken to 1K desk, there are only 24/50 seats in business that are booked as of today (10/23).

My concern is that I've been checking the same flight in the near term, and R availability does not seem to open up very frequently before 24-48 hours. So my question to the group is, at 24 hours, if not confirmed, should I check us in on the mobile app and deal with the dreaded "PNR Split" (which I admit I still don't understand), or should I wait to check-in until 2-3 hours before at the airport? Is there any benefit to doing one over the other?

Any guidance would be greatly appreciated.

PG