I would also add that almost no one makes a Whitney summit bid WELL rested. DUG
I had to laugh when I read this, because I don't know if I have EVER done a hike -- dayhike - backpack - multi day -- on more than 4 hours sleep! It always seems like I am putzing around the night before, so that bedtime and waketime run together. Clouds Rest starting at 5:00am? Wow -- that is early! When I did Cloud's Rest (as a dayhike from Sunrise Trail head) I think that we started at some obnoxiously late time after a 3 hour drive, like 10:00am or so....it was summer, so we still got back in time before dark, but then again, we were being chased the last 4 mile mile (def: "4 mile mile is when the last 1 mile feels like 4 miles) by killer mosquitoes!
The body betrays and the weather conspires, hopefully, not on the same day.