Remember also that the time in which videos go LIVE is not the only time you can watch them. They'll be available for some time.

If you're going to a session that you KNOW will have many "attendees" consider starting your stream at the half-hour instead of as soon as it goes live, or even later in the day.

(It's like going to a session in one of the 200 rooms that only has 50 seats, but there are 150 people wanting to get in to watch it. You can't see it then, but you CAN go back and watch the video later)