You'd need some crazy stuff to happen before even entertaining the idea. Right now, there are six undefeated teams outside the B1G that all need to drop a game or two (Alabama, Texas A&M, Washington, Baylor, West Virginia, and Clemson). This leaves Ohio State and TTUN as the last two undefeated teams. The Game needs to be a close one, where the Buckeyes barely edge out a win; something like a quadruple overtime would further the claim the runner-up should be in the playoff. And then, we'd need to go on and demolish Nebraska.
Now you need to eliminate three conference champions from contention. We're already assuming the B1G champion gets in, and it's very likely that Alabama will win the SEC and advance to the playoffs. So, that means the ACC, Pac12, and Big12 need to be shut out. Clemson will probably need two losses; these could come from FSU and the ACC championship, and with the way they're playing, that doesn't seem unlikely. Louisville needs to lose to Houston. This shuts out the ACC. To keep the Big12 out of the playoffs, Oklahoma needs to go all the way. Washington needs to find two losses, maybe losing to Utah twice? Once in the regular season, and another in the Pac12 championship, or one loss against Utah, and another against Colorado in the Pac12 championship. Then Utah needs to lose one game, against someone other than Washington. And, a non-power 5 team is not going to make the playoff this year, that chance went down the drain when Houston lost.
That's probably what it'd take for two teams from the B1G East to make the playoffs. It's not completely out of the cards just yet.