I did it a few years back with a club mate; I'd highly recommend it.
We did the Routes du Ventoux sportive (a French "sportive" which is otherwise known as as "race"
mass start, rolling road closure till Ventoux, prizes for top three in various categories and some crazy semi-pros at the sharp end of things) on the saturday, then rolled back on the Sunday to do the Cingles. We did Bedoin, Maulaucene and then Sault, which seems to be the standard order, with times of around 1:30 for the first two climbs (cant recall from Sault, but its the most straight forward climb). If I remember right we had a quick stop in Maulaucene for a coke and a snack, then went straight back up - stopping for an early lunch at Chalet Reynaurd before the decent to Sault.
Given you've got all day, it's a big day, but pretty straight forward and stress free when compared to timed and competitive events.
As ghyselinckr says, weather can play a part. I've been up and over Ventoux maybe 15 times now, including a long long ascent from Bedoin on a chunky hired tandem with my non-cycling partner (lucky she's only 42kg...) and I've been lucky to have nothing but perfect conditions. There are enough horror stories of crazy winds, rain or searing heat that I dont take that for granted though!