Yeah, this has happened loads of times for Wembley trips. I remember us fretting over making the last train back when we played Wigan if it went to ET and pens. Obviously Ben Fucking Watson alleviated our fears somewhat and we were back at Euston before 8.30 but I remember someone - can’t remember if it was a copper or a Virgin Trains staff member - telling us there was an extra unadvertised train reserved to leave about 15 minutes after the last official one at 9pm if it was needed.
Back in the 90s this wouldn’t have been so much of an issue as in those days the last train back to Manchester on a Saturday night was at 10pm. That said, I recall me and 3 others missing that one by about 2 minutes following a 3pm kick-off at QPR as we spent too much time in a pub 10 minutes walk from Euston and lost track of the time and we ended up kipping on the tiles at the station. After getting booted out of a club at about 3 in the morning that is!