I Personally dislike getting up before sunrise, but I really love watching the sunrise once I'm up. This couple braved the cold Mountain morning in Big Bear Lake to do a sunrise trash the dress session. I remember it was cold kept putting on and taking off her jacket. The photographs, we all agreed were worth it.
Some of the nicest light for portraits is Magic hour (the hour before sunset) and sunrise (about 30 minutes to an hour after that Beauty pops up). Nice light can be founded anytime of the day, it just takes a little more effort and photographic knowledge.