The Badgers have to beat Penn State no matter what. I also think Washington has to beat Colorado for them to be safe. Same thing with Clemson but their path is easier than either Wisconsin or Washington.
Washington beating a top 10 Colorado team cancels out UW beating a top 10 Penn State team. That's where it could get interesting in the comparisons. Washington has one loss to a top 15 USC team. The Badgers have two losses to top 10 teams. The Badgers beat LSU and Iowa and Nebraska - all teams ranked in the 20s. Washington beat Stanford - a top 20 team- and both Utah and WSU which are comparable to the Iowa and Nebraska wins.
So the way I see it - it's how the committee values 1 loss (versus 2 losses) and overall strength of schedule. I also think there could be the "eyeball test" in that Washington overall has looked better and more convincing.
The only way I see UW is assured of a spot is for Washington to lose and UW to win. That means both teams have 2 losses and it would be tough to deny the Badgers there.