We do plan on doing this route in a day and getting an alpine start (maybe 2amish) at Whitney Portal. My only other worry then becomes doing the Eledges at night, but from what I can see it just looks exposed and not technically demanding.
June brings the longest days of the year, and your should really not need to leave that early. Even a 5:00 AM departure "should" have you back at the trail head by 7:00 PM. Well before dark, and that allows 14 hours total. Even if you did end up going until after dark, you would be covering the easiest part of the trail at the end of the hike.
