A page on the portal where they can update their RSVP to an event, so they don't have to reach out to us with regrets (or worse, not reach out at all). Even better if it allowed hosts to manage their groups and update contact info/mark people RSVP'd or no longer coming.
This would be great. We currently have a homecoming event that has many parts and pieces. I picture something like this allowing us to send them to the portal to see what they have registered for as they always forget!