I am not downtown, so I have to ask a few questions.
1) Does Gen Con have areas established for napping? I am a night shift worker, and due to my life schedule, I may need a nap in the middle of a day. Since my hotel room is not in downtown, I can't just walk back to the room to nap.
2) Does Gen Con have a safe deposit box area to store items? If not, I suggest you establish an area in coordination with a shipping company. Use shipping boxes as drop off boxes to store people's stuff. Assign the box to the owner's badge account and ensure address is shipping address. Collect a fee for using service plus a deposit fee to cover packing material and shipping costs. Left over deposit money is either added to badge's account or donated to charity. The idea here is if the owner does not claim the box by Monday, they are packed and shipped.
I know there may be a problem with item 1, getting a lot of attendees who don't have housing that use the napping area to sleep, but I would consider this an opportunity for the local, state, and regional emergency management groups in testing emergency housing. I am very certain there will be a lot of volunteers in Gen Con for testing out disaster housing, with a small fee for cleaning up damages.