Pull up the rsvp page ahead of time. About 15 minutes before the time, they will open a page saying you are waiting to go into the queue. When it hits that time they will randomly give you a number. It will start dwindling down as they let people in. Ignore the estimated time as that will drastically decrease.
Don't be discouraged by a higher number, as many people have multiple browsers open and some just want to see if they could get in but will not purchase. Wait it out if you can, and keep your browser(s) open. Try to refrain from refreshing the page and just let it run its course.