I see posts of people travelling to Chamonix so thought I would share that the Mont Blanc Tunnel will be closed beginning September 4 for fifteen weeks. This will impact anyone wishing to travel to Courmayeur, for example, during a trip to Chamonix.
This is a message I received from the Courmayeur visitor center as my trip actually ends in Courmayeur:
"from September 4th the Mont Blanc tunnel will be closed for 15 weeks. We haven’t yet the timetable between Courmayeur and Chamonix (maybe through the Great Saint Bernard tunnel).
You should send us a new message at the end of August to have more dtails."
I am funding if difficult and expensive (400+ euros) to get transport from Courmayeur to the Geneva Airport, for example, on September 8. I could always roll the dice and hope the cable cars are all running, but that is a bit risky.
Hope this helps someone.