You Have to understand how sagarin ratings are structured. It doesn’t matter if you FCS or FBS. If you 42 (76.3) playing 128 (65.3), you are -11(for example). It doesnt matter as much if you win, but how much you win by. If you are -11, and win by 3, you are affected negatively. If you win by 30 you boost your sagarin. Yes, playing higher rated team helps. If you are +10 and lose by 7, your rating holds its own. It’s a very good system to compare teams at both DI levels based on how it is structured. It’s a much bigger boost covering vs the 1 ranked team vs 120 however.
Schedule ranking also plays a factor. MN at 7-6 is likely ranked much higher with a schedule ranking of 43, than it would if their schedule ranking of 83.
If MN played Clemson at a neutral site, they would be -27, 103 -76. If they lost by 14 or less, it would have nice impact on their sagarin, as would playing the 1 ranked team. MN can boost their sagarin playing #1 or #120, but they have to cover.