My wife is booking into an Earls Court hotel for tomorrows Barbra Streisand concert at The O2. How much time should she allow for tube travel between Earls Court and North Greenwich to be in good time for 8pm start?
about an hour - it shouldn't take more than about 45 minutes, but don't cut it too fine; it only takes one broken down train to make a mess of timetables. Check on the TfL website or the BBC's one before setting out to make sure everything's running ok.
She should get their early if she can - there are several bars restaurants inside the O2. If she's got loads of time she could even get the boat there from Waterloo!