Well, I think I'm ok with going ahead and trying it. I don't know how big that location is, obviously, but ours here is pretty big and I don't think there's ever much of a wait time. Although, we might be taking up ALL of the available highchairs, lol! If you guys are not comfortable with the "try it and see" approach, then we can come up with an alternative idea. I'd like to think that at 9:30 in the morning it wouldn't be packed, but then again this is Saturday so people might be going for late breakfast/brunch, etc.
PS--Andrew is getting so excited. This morning, he said "today is Thursday. Only two more days to go!" and when I asked "two more days til what?" he said "until Saturday and we go to the museum!" LOL I was so proud of him!