Given that its not selling much you could probably show up 5 minutes before the show without issue.Most shows they might have 3-4 rows in the front left reserved for it but unless its a very popular group those rows are barely half full so about 5 minutes before show time they will leave one row for the dining plan but the others they open them up and everybody from regular seating nearby rushes to the rows they opened up.Just my experience lately,I've seen 12 of the 18 groups so far so I do go a lot.If you buy it the theater is open hours before for the first show so you can get there as early as you want but note the first show is usually the most crowded.For the second and third show they let the dining plan in about 20 minutes before and 5 minutes later they let in the regular line.