Join Date: Mar 2001
Location: Fort Worth TX
Programs: Earned status with AA, DL, SPG, HH, Hyatt, Marriott, Seabourn, NCL, National, Hertz...I miss my bed!
Posts: 10,927
I missed the 45 minute check-in cut off for a Mexico flight a few months ago and AA rebooked me on a later flight.
YMMV - I don't know that there is a blanket answer without knowing specifics of the circumstances.