You need some consequences for his getting out of bed that early. He's clearly still tired because he goes back to sleep. My daughter would be an early riser, too, but since she's been old enough to understand (which is like, what, four?) our rule has been that she has to stay in the bed until seven, other than going to the bathroom. She does not wake us up unless she's throwing up or has an emergency. Your son is old enough to understand that he needs to stay in bed until seven. Tell him no ipad, no books, just lay there. And if he starts getting up and waking people up, consequences. Just pick a consequence that seems logical to you. And make him stay awake until it's time for school.
Also, third grade is old enough to handle his own breakfast if he's going to INSIST on being up. It would not be a fun breakfast like poptarts, it would be fruit and cold (not sugary) cereal. If he makes a mess, make him clean it up.
You can make this early waking very inconvenient for him. It should be at least as inconvenient for him as it is for you.