I'm a bit confused, are you inferring that the ND fan base is shrinking? I don't think that's the case...and sorry if I'm misinterpreting. The portion of the fan base that generally attend games, might be on the older, "blue-blood" side. But if you look at the TV ratings, ND fandom isn't going anywhere. I'm not an alum, but my grandparents grew up in South Bend and relocated to MI, and I'm a third, hell maybe even fourth generation of ND fans in the family. And I don't anticipate that changing.
I think the difference is what Beau kind of alluded to: Are millennials or Gen Z as likely to make a trip and spend more money with the enhancements TV has made? At-home entertainment is wildly advanced compared to what the "blue-bloods" experienced. So as season ticket holders go away, I think there's less and less taking their spots, and fans like me pick my battles and attend 2-3 times a year as opposed to going for all 6 or 7. I have colleagues who are scUM alum who gave up their season tickets for the same reason; they'd rather just watch from home and go to a game or two every year.
You schedule programs from the group of 5 (Cincy is a different story) be prepared to have empty seats charging $50 or so a pop, plus travel and lodging expenses.
