day.
sure, a lot of it was manufactured stuff that isn't directly linked to the game. But, it filled the campus with college feeling and filled the campus with people.
BYU has enough talented students to sing, play music, etc. as ND. I like your Poly idea, etc. Bring some of the flavor of the Polynesian Cultural Center to Provo. Have the a capella singing groups sing. Have bands (rock, country, whatever) playing on campus. Have the Cougarettes perform. Have a few live Studio C type skits for 15-30 minutes.
I particularly enjoyed (as you said) that at EVERY building you walked into (including the engineering bldg where i went just to take a leak) was manned by volunteers at the door saying "welcome to Notre Dame". I truly felt welcomed and felt that EVERYONE was there for the game and the experience. When you act like it is a special thing to come to your campus, people will start to feel that it IS a special place to come and visit.
At BYU, the campus is a ghost town all Saturday and its more of a "Hey, BTW, we have a game here tonight".