I will be curious to see how tomorrow's game ranks as far as viewership goes. As the article points out, it is in prime time, and every fanbase of a team with a shot at the Playoff will be a Northwestern fan for a night.
We've actually had some highly rated games this year, including one of our more highly rated games of the past 10 years:
Michigan (FOX) - 3.618 million
Nebraska (ABC) - 2.450 million
Wisconsin (FOX) - 2.241 million
Purdue (ESPN) - 1.741 million
Michigan State (FS1) - 620 thousand
Duke (ESPNU) - 337 thousand
For some reference, our top 4 games of the Fitz era (AFAIK):
2013 Ohio State (ABC) - 7.36 million
2008 Missouri (ESPN) - 6.076 million
2010 Auburn (ESPN) - 5.685 million
2017 Kentucky (ESPN) - 4.626 million
(Sidenote: this is why I stress winning bowl games, they're often our highest rated game of the season and when we get the most non-Big Ten viewers to impress)
For this game, I'd imagine it looks similar to our Ohio State/Michigan games which typically draw a number in the 3-4 million range. Then again there's a lot of hype in this game on the Notre Dame side and maybe a lot of people will think it's one of the few remaining chances they get knocked off, so that gives it a chance at 4+ million viewers.
On the opposite side, you do have Alabama-LSU starting a bit after our game, and that will be the most viewed of the night by far, but it shouldn't affect our game reaching the 3-4 million range at least.
Partially depends on whether Alabama-LSU is a blowout while our game is close, if so, we could reach 4-5 million viewers fairly easily.