Change to a road bike or ride a hybrid if I was Primoz?
I'd ride the TT and it's gearing to the top of the climb before the Belle Filles. Change bikes there with a downhill to minimize any time loss and allow you to spin into the position that works for big ass climbs. You're also basically hitting a wall at the start with that climb and it'd be better to have gearing and the climbing position that got you this far to bring it home.
If I was Ritchie or MAL I'd go hybrid. They're both smaller guys and can probably get as aero as they need to be and not lose any critical time. Ritchie may be faster on his TT bike than MAL to the point he'd go either way.
WVA? Give him a cyclocross bike and stand back! He'll do well if they let him loose. They may want him to keep the powder dry for the Champs glory that he could get.
Dumo? I'd let him do what he wants and he may be in the mindset to go faster than anyone. He'd do a bike swap IMO.
Tadej should swap and he's nimble enough to handle the change. If he's at his best he can challenge Roglic, WVA...all of them. Not sure if he has that snap and he'll be on his own the whole way.
Not sure who I'd like to win, though. Lot of worthy guys.