I've done most of these passes in groups of 4-8 cars, we always fill when available - 98+ is not always on sale so we tend to stop when half full in case we have to top up with 95.
Never had any issues on any trips other than police stops, speeding tickets following us home & the occasional issue finding hotels en route later in the day.
We rarely drive after dark as we like to have a beer in hand to chat & laugh about the day we've just had.
The Route Napoleon is a personal favourite but be careful it's very easy to push on & get yourself into trouble with the law, we found out the hard way that 140+kph is not acceptable in a 90kph zone, we were fined, cars were impounded for 24hrs & we received a 3 month ban from driving in France - this made the drive back to Calais extremely bum twitchy - but we still go back to France, Germany & Italy every 18 months or so as the roads are epic - the Dolomites are fantastic.!!
This Autumn we're going the Pyrenees, not been in a group before but apparently the roads are quiet, well surfaced & great fun - 8 cars this trip - should be a blast.
Enjoy you trip..!!
