Saturday: Hike 6miles to Trail Camp. Camp for the night.
Sunday: wake up 4-5am. Hike to Whitney and then return to camp, pack out and hike to our car the same day. Should arrive at the car around 5pm. This day will be brutal for sure.
Two of us did exactly this in Aug 9, 2012
515 up at Trailcamp
615 watched alpenglow and left Trailcamp
1130 left summit
235 back at Trailcamp, retrieved tent
I cannot go down much faster than up, so your times may be quicker . Tiring , yes, brutal, no.