Apologies if this question is in the wrong place
Approx how long does would it take to get from the O2 to Stratford train station after a concert. I need to catch the last train at 23.40. The concert finishes at approx 10.45. Thank you.

If you use the journey planner at tfl.gov.uk it says 26-29 minutes, but that assumes you can walk from the O2 to North Greenwich tube station in 9 minutes. That might not be realistic if it's very crowded.

Thanks.
I need to get to Stratford. It says 9 minutes by tube but that's obviously not taking into consideration the mass exodus after a concert before you manage to get to the tube station.
Has anyone done this journey please?