So my quick answer, barring a spell of premature excitement, would be that it depends on how Carapaz is feeling. If he's on a good day I see only the bona fide podium threats hanging on in Porte's slipstream as we approach. If he looks a bit shaky then, if no one is meddlesome enough to find out for us if he's bluffing, it might be a fairly big group riding coach at that point. But again, even given a disappointing lack of curiosity among the leaders, around the time they hit that banner I really do expect someone to make a proper bid to jump the tracks.
The more that Ineos drill it, the more riders are dropped and the more time they lose. The softer that Ineos pace it, the more riders attack, and earlier the attacks if the tempo is slow. So I don't see how very little happens here (though of course it might be little enough to dissatisfy the forum), especially with Bora having 4 riders in the mix.
At worst we may get a Grand Columbierre 2020 Tour situation, but even those unlikely chances are reduced further because A) a top contender was already dropped near the bottom (Bernal), and B) Sepp Kuss was being Sepp Kuss.
Maybe if someone like Landa dropped early and was already losing minutes then that might satisfy other contenders, but then you'd also need Porte to ride like Kuss did then, and history says that Richie won't leave anything in reserve. Of course the other alternative is that Porte has his stage 9 crash early and Ineos don't ride hard and the other teams think that's only because he's out, and do nothing either.
But Porte's stage 9 luck is going to turn