I don’t see a scenario where we’re #5.
Assuming we don’t play in the conference championship game, we’re behind at least the loser of it.
If Ohio State loses to Michigan and we make the conference championship game and lose to Oregon, we’re again behind Ohio State.
If Ohio State loses to Michigan and we make the conference championship game and beat Oregon, we’re the 1-seed in all likelihood.
Assuming we don’t play in the conference championship game, we’re behind at least the loser of it.
If Ohio State loses to Michigan and we make the conference championship game and lose to Oregon, we’re again behind Ohio State.
If Ohio State loses to Michigan and we make the conference championship game and beat Oregon, we’re the 1-seed in all likelihood.