WE have done 'Ohana before the party, while staying at Poly, and last year we were booked for Concourse but actually walked up to the CM at check in at LTT and she was able to seat us within 20 minutes, before 6PM. We were done before the party started. I'd still advise having a back up plan though, you can't count on a walk up, it depends on when you are going to a party.