If the banquet must happen on Saturday night, then I think the answer would be to offer something in there as an additional attraction to get people to go: eg exclusive debut of a new game or maybe have the autograph session as part of banquet. The idea would be to find something to attract people to go rather then close the hall and force them. This year maybe having WOZ in there for exclusive play by attendees would have been enough of a hook. I just think using a carrot approach instead of the stick of closing the hall would be better.

As for having more games for free play, a better, easier to get incentive for bringing games has been mentioned frequently. If there was some assistance to local residents with moving games, you might have many more come in. You could offer incentives to locals with trucks/vans to have a route to pick up and move games. Just a thought.