I don't think SC is going to look nearly as good against UW's defense as they are against Cal's piss-poor defense.
That's not to say that they won't move the ball, but imo, as dominant as they looked last night, you have to figure in how terrible Cal's defense is.
Washington is extremely tough in Seattle no matter what, and this year they are also a very good team, especially in the trenches. It's not going to be as easy for Darnold as it was last night. And then you have the propensity to turn the ball over. It's a real problem for them. It's one thing to say that this defense or that defense forced turnovers against them, but they turn the ball over multiple times a game. That's not going to work in Seattle.
I'm not going to go so far as to say that there's no way that SC can win the game, that would be silly, but I don't think it's the most likely outcome. If I had to guess right now, without any additional injuries to either team, I'd say that UW would win a one score game, with one or more SC turnovers being important factors.