It probably could be. When I met with he dean he told me it isn't advisable, but that successfully students typically go to class the 20hrs a week and study an additional 40 hrs a week. So if you could find a flexible job to add on top of a 60hr a week commitment, you probably could swing it. Also you might not find you "need" or "want" to study 8 hrs a day in addition to classes, but that 5 hrs works for you. Then you'd have a 45 hr commitment a week. Personally, I think finding free time for myself within the program will be useful in preventing burn out and having a healthy and happy life. Kudos to you if you're someone who can do it all though!
Thank you so much for the information!