I haven't watched the video yet, but I assume it's shot somewhere along this path.
http://www.bikely.com/maps/bike-path/Projet-Alpes08-Etappe2
123.4 km. From there, Google Earth or Maps should be able to give elevation changes, in principle.
Alternatively, this site says the are several Venosc routes.
http://www.ecycletours.com/content2008/02-itinerary.htm
HTH a bit.
Cheers,
Scott.