I will limit this discussion to the three 1-loss B1G teams: Michigan, Ohio State, and Iowa. The two-loss teams (UW and PSU) have a theoretical shot but it would require chaos because there would need to be a whole bunch of upsets nationally before a 2-loss B1G Champion got in and, in Penn State's case, they would need a whole lot of upsets just to get into their divisional race.
#5, 7-1 Michigan:
The Wolverines clearly have the best CFP chance of the B1G teams. We had a discussion last week about whether or not they control their own destiny. I'm still not 100% convinced that they do and Ohio State's blowout loss to Purdue didn't help the Wolverines on that front. In theory, I could see a 12-1 Michigan them finishing behind a 12-1 or 11-1 non-champion Bama along with ND and the SEC and ACC Champions.
#11, 7-1 Ohio State:
IMHO, Ohio State's playoff chances are MUCH worse than Michigan's because the chances of a 12-1 Ohio State being behind a 12-1 or 11-1 non-champion Bama are much greater. Additionally, a 12-1 Ohio State would probably finish behind a 12-1 Texas or Oklahoma as well.
#18, 6-1 Iowa:
Iowa's loss is obviously better than Ohio State's, but the major problem for the Hawkeyes is that they do not control their own destiny even in the B1G-W. Iowa's chances of getting in at 11-1 are somewhere between slim and none so they basically are not in the discussion unless/until Wisconsin loses another game.