Prob 2 – 2.5 hrs up Llanberris (if pushing)
3ish up Telegraph/Rangers – I prefer it, but most would think I was insane.
Descent time – very variable and dependant on your abilites, luck with punctures and tollerance for lactic acid build up.
I’d do the most part of Rangers in under 15 mins if I didn’t have to stop now and again to ease the burning in my quads
So call it 20 – 30 mins and then another 30 for Telegraph Valley and getting back to car.
Edit: FWIW I’ve not done it early doors, quite into the evening descents.