Stay calm, either in the lounge (or ideally a bar which you can see the gate from) and have another drink while you wait for the queue to die down. I've never been unable to stow a normal sized laptop bag (the crew are generally helpful if they can see you're not taking the mickey), never really understood the desire to sit on an plane any longer than I needed to. Unless it's easyjet/ryanair and then deploy the sharp elbows and 1mm less than regulation baggage.