watched on col de madelaeine 2 years ago. drove up the night before at about 9pm and by then there were 0 parking spaces on the ENTIRE mountain.
given the mountain is 26km long you can imagine how busy it was!
eventually left the van hanging half of a cliff and slept in it overnight through a thunderstorm.
this was followed by a ride up the hill at first light, and then about 8 or 9 hours of waiting in 30+ degrees heat.
once the tour comes through the road is re-opened and is campervan bedlam!
absolutely amazing 24hrs, had a cracking time with some PROPER fanatics of various nations, weas also well impressed by a proper french bread van doing the rounds at 7am delivering to the campers!
but… i really, really wouldn’t have liked to have a family onboard.
no bogs, scorching hot, sleeping in van etc etc.
this experience is probably limited to the high mountain passes only mind..