We have same issue, but just not as early
Dexter also is not the one to sleep in, unlike his mommy
We don't crate him at night, he sleeps in his own bed, but then jumps up on our bed in the morning and sleeps a bit more there. However still wake up early.
What I started doing is closing our blinds to make the room dark, and I noticed that he sleeps in later and actually I get to wake up with alarm and not earlier.
Good luck!