Unlikely but not out of the picture completely.
Undefeated teams:
Alabama
LSU
Boise St.
Ok St.
Stanford
Clemson
Kansas St.
Houston
OK State has a tough schedule Baylor, Kansas St. #11, Texas Tech, Iowa St., and Oklahoma #3.
Stanford has a fairly tough schedule USC, Oregon St., Oregon #10, California, and Notre Dame.
Clemson has a average schedule but possible for them at this point with SC without Lattimore... Georgia Tech #22, Wake Forest, NC St., and South Carolina #22.
Kansas St. real tough schedule Oklahoma #3, Oklahoma St. #4, Texas A&M #17, Texas #24, and Iowa St.
Houston has an easy schedule with Rice, UAB, Tulane, Southern Methodist, and Tulsa but they are so far back I don't think they will be buster.
Boise St. has very winnable remaining schedule UNLV, TCU, San Diego St., Wyoming, and New Mexico.
Based on the following I could see the following undefeated at the end of the year Alabama or LSU, Houston, Boise St. and Clemson.
Houston is not going to jump a 1-lose Alabama or LSU. The rest could but some of these teams play each or play tough remaining schedules. I am not for sure Boise St. would jump a 1-lose Alabama/LSU but it could be close. Clemson has a winnable remaining schedule and could be in there against the winner of LSU/Bama. If Clemson loses to me it might open for a LSU/Bama rematch in the NC.