Anything is possible, but a lot of things would have to happen to get to a place where fewer than 4 P5 teams have fewer than 2 losses.
ACC - Look at Clemson's remaining schedule. Clemson losing two games against that schedule is about as likely as the moon falling out of orbit and crashing into the earth. But if they lose one, might they get passed over in favor of a conference champ such as 11-2 Michigan or 11-2 Texas?
Big Ten - Most likely possibilities are (1) Michigan loses to Penn State; Michigan beats Ohio State, or (2) Michigan-Ohio State winner loses Big Ten CCG. Possible.
Big 12 - Possible. OU and WVU could each lose a game, or OU wins out but loses to UT in the CCG.
Notre Dame - Not likely that they'll lose two. It's possible that they lose one and, in that case, see comment above about Clemson.
Pac-12 - Likely. Wazzu almost always has one poor game in them (hopefully this week
), and to get to 12-1 they would have to beat Washington and (probably) Utah.
SEC - Not likely because a lot would have to happen. Something like: LSU beats Bama; LSU loses to TAMU; Bama loses to Auburn; LSU wins CCG.