Multiple clients have requested that we set the webinar to stop allowing more registrations after a certain date or time. As it stands, the only way to accomplish this is to manually change the maximum number of registrations to match the current number of registrations at the time they want to cut off registrations.
Hi Chancy,
What you state is true: There is currently no way to set an expiration 'time' for webinar registrations. We'll keep this up as an enhancement 'idea' for other GoTo Organizers to weigh in on.