I was hoping to stay in Morzine during the TDF, was hoping it wouldn't book up that quickly.
There is a bus, but I'm not too sure on details, I don't think it was that frequent. The Supermorzine lift runs from Morzine towards Avoriaz, but not right to it, there's still a fairly long walk (it never seemed that far on a bike), but the lift is not too far from the road, so they could watch part way up.
They need to be wary of the lifts closing though. I did a fair bit of walking this year as I'd broken my arm and couldn't ride, I met my boyfriend and his mates at the restaurant in Linderettes (below Avoriaz), but a storm broke out just as we got there, they didn't open the lift back up until 4pm, I had to run from Avoriaz to catch the lift back into Morzine before it shut for the day, otherwise it would've been about a 10 mile walk down the road and I'd already walked 8+ miles that day. I got there in time, but the lift had broken and they told me they didn't think it would be fixed that day, luckly they did manage to fix it. I would imagine they would keep the lift open longer on that day.