As stated above- some of the lifts will be VERY busy- I’d suggest that you get hold of a copy of the route and avoid those lifts, at least early on in the day. Perhaps by midday you will be OK, depending upon where you are.
You can use any valid pass you want, it will not need to be PPDS specific. FWIW, the PPDS pass is valid for the entire domaine and not just for a single day (I think) so ask around- you might be able to snaffle a cheap pass from someone after the event. It’s worked for me in the past. One one trip a mate managed to get a whole week’s worth of riding that way.