Even though there are no indications that Notre Dame is wavering on its decision to keep charting an independent path rather than join the Big Ten, it still makes a lot of sense.
And just in case that changes, the possibilities of a two-division Big Ten are intriguing. There's no obvious can't-miss alignment scenario. But here are a couple that could work.
NORTH: Michigan, Michigan State, Ohio State, Iowa, Minnesota, Wisconsin
SOUTH: Illinois, Northwestern, Penn State, Notre Dame, Indiana, Purdue
OR. . . .
EAST: Notre Dame, Michigan, Michigan State, Ohio State, Indiana, Purdue
WEST: Illinois, Northwestern, Penn State, Iowa, Minnesota, Wisconsin
No matter how it's done, preserving traditional rivalries would be important. I don't see Michigan, Michigan State and Ohio State ever being separated. Similarly, Iowa, Minnesota and Wisconsin probably shouldn't be separated. Indiana-Purdue, and Illinois-Northwestern, also are rivalries that should be preserved. And remember, it's not like the divisions would be all that separate. Teams would play the schools in the other division half the time.
The North-South plan would have the advantage of letting Penn State and Notre Dame, who met regularly before Penn State joined the Big Ten, anchor the South. It also would make the North a very rugged division, considering that Iowa and Wisconsin have established themselves as strong alternatives to traditional powers Ohio State and Michigan.
My East-West plan would allow the Irish to maintain their annual rivalries with Michigan, Michigan State and Purdue. It also would keep the three Indiana schools together. (And if Dallas can be in the NFC East, Penn State can be in the Big Ten West.) Nor would I be a fan of non-directional names, such as the ACC's Atlantic and Coastal divisions.
Other possibiliites would be the Grange and Nagurski divisions. Or the (Wayne) Duke and (Jim) Delany divisions. Now you see the appeal of the good old North-South.
I tend to favor my North-South plan, because I think ND-Michigan-Ohio State in one division (the East) would be too many traditional powers in one place. On the other hand, with the North-South arrangment, the Ohio State/Michigan-driven North still would be awfully rugged, considering what Iowa and Wisconsin have been doing.
The only way to achieve better balance, though, would be to break up more rivalries. And that doesn't make sense to me, particularly because predicting which programs are going to advance and decline down the road is not easy to do.