Remember also that this is not the course that goes straight up Ventoux. You go through the middle undulating section of the France course first, through the Ballon sprint arch, then up the Petit KOM, before joining Ventoux at the junction there. You're actually only on Ventoux itself for just over 2km.
If anyone wants video footage of the exact route and where the finish is, here's a stream of someone doing the full La Reine course - our finish line is going to be roughly where her in-game clock hits about 28½ minutes (maybe a few seconds before that).
View: https://www.youtube.com/watch?v=mh8PsyfLR_o