If both Washington and Clemson lose in their conference championship games the committee could be squarely facing the possibility of having to put 3 Big Ten teams into the final 4 playoff spots. By their own rankings they would be the next best 3 teams left but...but...I don't think they'd have the balls to do it.
Two big Ten teams plausible - Ohio State and winner of Wisconsin-Penn St. (Wisconsin for short). And it only takes a loss by Washington for Wisconsin to get the nod, as beating LSU on the road is a bit more impressive than beating Rutgers at home.
Even if Clemson loses, their schedule is a bit tougher than Michigan’s, and neither would be a conference champion. For political reasons, I don’t think Michigan will get in - as that would make it Alabama vs. the Big Ten.