Eric,
I hope you have read
Shri S's report.
He started from Whitney Portal at 11 AM, made Trail Camp by 4 pm. It might take you longer, but you certainly don't need to start too early the first day. Try to get some sleep Friday night somewhere.
Shri was lucky that he didn't get hit with altitude issues. Many people do who camp at Trail Camp the first night. If all goes well, and you start early from Trail Camp, you could make it back to the car for a late drive home. I've done that sometimes -- share the driving and trade off taking naps on the trip home.
