Ugh. For three weeks now my oldest has been getting up between 4:45 and 5:15. I don't know how to fix this, and it's killing us all slowly.
Time to get him a signal of how late he is allowed to make sounds and get out of his room. Maybe a little light on a timer, or music on a timer. Awake before that, means quiet play.
You could put a cup of water on his room, and maybe something to eat too, when he is asleep, so he will have something in the mornings.