We are talking some ego here, a fair bit of hubris. I suspect you are right with a stage win, it just depends on how close it is. If there is a break that is not worth catching, he can play it easier. Where it gets interesting is if the climb truly is everyone hotting it up, but he could still make a 30+ second acceleration to win it, he might just do it to get the win and flip the bird to everyone. It won't seem quite as radioactive, but there's no real need.
He will fail the doping IQ test if he needlessly pummels a climb like this and sets some sort of stupid time. It's possible but unlikely.
As for the TT, it is harder to extrapolate the exact watts. Which means he does have that in the back pocket if he needs a bit more buffer. Gianetti and company want to win the whole shebang, so no point in being completely stupid.