I'm going to have a large group at the game Saturday, and I'm trying to find a MSU sponsored tailgate that would feed them. Mostly made up of high school students.
The Alumni Tent does a tailgate every game. They serve Little Dewey for the games after lunch and breakfast for the early games. It's right in front of M Club building.
The College of Engineering also has one most of the time, but I don't know about this game. I don't think you'll have any trouble finding a welcoming tailgate though, school-sponsored or not, particularly once they find out you're prospective students.