I already climbed the path leading to the finish line and this stage is definitely for an explosive rider (Valverde, Albasini, Kwiatko...). It's going to be hard to gain 15-20s during the ascent of La Mauselaine... The best way to gain time would be to attack in the cat.2 Grosse Pierre. This short pass is very steep and regular, and if someone had a bad day, he might lose the TdF here.
I don't think the first pass (Croix des Moinats) will change anything in the race.
I'm looking forward to seeing the TdF coming in Elsass. This is my region.