Did the route a few years ago but not on the official day, just followed my mate who downloaded a GPS track. I don't recall any particularly gnarly sections but I know there are optional downhill sections, which I guess we missed.
How difficult are the optional downhill sections? I've done a few of the reds around Morzine and Les Gets before. Also did the Grande Conche if anyone knows that one?
Second question is regarding food/drinks on the day - how often are they and what kind of things are available? Don't want to carry 3L of water if there are regular stops.