You could always stay in Morzine and drive up on the morning of the event
Better yet, you could drive up on the morning, register there, then start from Morzine. There’s a lot more accomodation and you have more chance of getting back into town if running late.
A couple of tips
– You don’t need a DH bike but DH tyres are a good idea
– Start early. It’s a long day, and you can get some big queues
– It’s really tempting to stay a long while at all of the rest stops, but I’d save that for the later part of the day. You are a bit against the clock.
– There’s a fair amount of climbing, so beware a full-facer and too much armour. The more you pare back, the greater the care you need to have on the DH sections. You can avoid these, obviously, but that to me is a bit of a waste.
– If you’re starting from Morzine, do the SuperMorzine leg first.
– Book a restaurant for Saturday night otherwise you’ll never get anywhere to eat.
Hope this helps.