The tube stations nearby are often closed after big concerts to avoid crushing and overcrowding. The police only let in a few at a time and hold crowds back to prevent too many being on the platform. So unless you're one of the earliest away, it could mean a wait of up to an hour if you're unlucky. This means people spread out and grab buses or walk to other tube stations instead or take an uber a few stations down the line, which is what my daughter did last time.
Unless you're going by coach??