Weekdays are usually less crowded than weekends, especially at the beginning of the month. They block the reserved seats by the number of packages they sell, so how big the section is depends on the number. You would have to decide if you want to have dinner before or after the show. We've done it both ways and prefer after, that way you don't have to worry about the time and you can also have leftovers boxed and take them with you. It's alot to eat, so we just have the dessert boxed.
Last year they went on sale in late August, other years were earlier, like June. They don't publish the narrators until late October. You can cancel or change your date up to 48 hours before the show.