As an ND alumni, BucksLAN, I must disagree with your statement that OSU has the best traveling fanbase in the sport. Although you can find all kinds of surveys on the topic, each reaching a different conclusion, I think ND has long been considered to have the best traveling fanbase in CFB. Not necessarily the loudest or most vociferous fanbase, but the one that travels the best. Much of that goes back to the Knute Rockne days, with the subway alumni and when ND was a national brand and college football was a regional sport. It is one of the reasons ND is consistently a plum choice for bowl games, even when its record isn't the best. Bowl committees know ND fans will fill the seats. That said, Ohio State is also very high on the list, so I don't disagree that Buckeyes fans travel very well. And of course, this is a home game for ND so it matters not that ND travels well.
There was an article written by Pete Sampson in The Athletic a couple of days ago detailing what ND is doing this year to try and keep Buckeyes fans from taking over ND Stadium, like UGA did a few years ago, and Nebraska did before that. The article is behind a pay wall, so you have to be a subsciber to get it, but here it is:
Notre Dame Stadium is a destination for opposing fans, including infamous Georgia and Nebraska invasions. How can it limit Ohio State red?
theathletic.com
(Plug: A few years ago I took out a subscription to The Athletic when they were running a special, and I haven't regretted it. I pay $7.99 per month now, and it is well worth it to me. I closely follow MLB, the NFL and CFB, and they have great content on all major sports. What I enjoy is that they do in-depth pieces on many subjects. For anyone that loves sports, incuding ND football, I recommend The Athletic.)
What makes me think this game will be different from UGA and Nebraska is that, first, this game is probably not a "bucket list" trip for most OSU fans. While we haven't played them many times, we have played them recently enough. When UGA came here a few years ago, many in its fanbase were willing to pay anything--and I mean ANYTHING--to see a game at historic ND Stadium. Southerners tend to appreciate history a little bit more than most northerners, and they were coming to the game hook or crook. I had a professional colleague in Atlanta who is a UGA grad and huge fan, and he paid $10,000 for 2 tickets for him and his wife to attend the game. I told him he is insane. He told me he would have gladly paid more!
Second, according to The Athletic article, ND isn't making some of the same dumb mistakes it made with UGA and Nebraska that made it easier for visitors to get tickets.
It still comes down to whether a sufficient number of ND season ticket holders will sell their tickets--and their souls!--for a chance to make some big money. I hope that doesn't happen, and I don't believe it will, but we will see soon enough. I think Yahoo's prediction of 30,000 Buckeyes fans being in the stands is fantasy.