A 757 to 777 swap would lead to a flight with plenty of empty seats, so the trauma wouldn't be bad.

Once in my 1K days I had a 777 to 757 swap on LAX-IAD. Lots of people were getting bumped off of their flight to connect to their transatlantic flights at IAD and there was a real commotion at the gate at LAX. I terminate at IAD and was in no hurry, so I volunteered my seat and got a first class seat plus flight credits along with a big smile from the GA to take a flight just 50 minutes later.