We'll see about that. He'll be two weeks in first grade, I'm ready to pick him up if anything gets bad, so it's up to him. I think it's early, 3rd grade seems fine to me for such trips. But when it comes to adjusting to a new group, especially when the kids are grade 1-9 and only around 40 total, it might be fine to get o know them deeper right away, he'll be scared otherwise.
Discussion
I think you'll know by the time he goes. He might find someone that he really clicks with and it'll be fun.