Based on their remaining schedule, it looks like the Irish have 3 potential "big games" left. Two against ranked teams (Duke and USC) and one against currently unranked Clemson.

OPPONENT     SCORE       DATE TIME (ET)     TV          LOCATION
vs. Navy W, 42-3 Saturday, Aug. 26 2:30 p.m. NBC/Peacock Dublin, Ireland
vs. Tennessee State W, 56-3 Saturday, Sept. 2 3:30 p.m. NBC/Peacock South Bend, 
at NC State W, 45-24 Saturday. Sept. 9 12 p.m. ABC Raleigh, N.C.
vs. Central Michigan W, 41-17 Saturday, Sept. 16 2:30 p.m. Peacock South Bend,
vs. No. 6 Ohio State L, 17-14 Saturday, Sept. 23 7:30 p.m. NBC/Peacock South
at No. 17 Duke -- Saturday, Sept. 30 TBD TBD Durham, N.C.
at Louisville -- Saturday, Oct. 7 TBD TBD Louisville, Ky.
vs. No. 6 USC -- Saturday, Oct. 14 7:30 p.m. NBC/Peacock South Bend, Ind.
vs. Pitt -- Saturday, Oct. 28 3:30 p.m. NBC/Peacock South Bend, Ind.
at Clemson -- Saturday, Nov. 4 TBD ABC Clemson, S.C.
vs. Wake Forest -- Saturday, Nov. 18 3:30 p.m. NBC/Peacock South Bend, Ind.
at Stanford -- Saturday, Nov. 25 TBD TBD Palo Alto, Calif.

It would seem we hold a game and half lead over the Irish and they should not impact us in a head to head CFP decision. So, I'm thinking we would want ND to win out and had losses to Duke, USC and Clemson. Getting Duke and USC closer to the two loss world and improving the Irish ranking. That could give the Buckeyes the "best win" in an CFP discussion.

so, Go Irish ????  

(Yes, I know "just win all your games", "take care of your business" are always good answers but things don't always go that way)