I actually did this event last year, though I wasn’t racing I was just aiming to finish and not be dead last(which I did).
but will the front packs ride past them? Or will it be pit-stop style grab what you can and jump back on the bike?
I didn’t run in the front packs, but based on their times my guess is they weren’t stopping at feed stations, and if they were then it was a REALLY quick stop so as to not lose the group. The front runners are completing the stages in about 4 hours, which is just short enough that you could probably hold your own food and not need to stop anywhere. I hope you’re ready for it as the front runners are VERY fast riders, some were even national champions.
Do packs even form in Haute Route events?
Definitely. It’s like any other large group ride, in that you’ll eventually settle in with people who are of similar fitness as you. I ended up riding with a couple of guys for all three days as we were all very close in fitness levels.
My guess is you’ll be in the top third of riders with your FTP, but to be right on the front is a whole other level of fitness and ability. Keep your expectations in check.