I’ve not done the Marmotte but the Haute Route stage 3 in 2012 was Madeleine, Galndon and AdH – and that was about 38C in the valley at the bottom of AdH. We had the bike escort handing out water which I was mainly pouring on my feet – I was suffering with shoes that were just a little narrow for me and with the heat-driven swelling I was in agony.
Moral – make sure your shoes are big enough.
For the roll call – my mate Darren. He only started training 10 weeks ago, got a late entry. He’ll be fine though, lots of previous experience and responds well to training.