Sleep is on my mind today...

I posted a while ago about LO's early morning wake-ups and was hoping it was just a phase. Unfortunately waking up between 5:00 and 5:30am seems to be the norm and the rare 6/6:30 wake-ups are more of a phase

Usually he is crying/screaming when he wakes up and is still really tired, we've tried rocking him back to sleep, bringing him in our bed, and leaving him for a little while. When we go get him he will sometimes fall back to sleep and other times try to get up and play. When we leave him he usually screams louder, very rarely he'll go back to sleep.

This is not working for any of us. We need to change something. Any advice? If CIO is the solution we are open to that, but open to other options as well!

In case it helps you sleep experts to diagnose the problem or offer a solution: DS is 16 months, and bed time is 7pm. He takes one nap that can be anywhere from 1-2.5 hours, he's in daycare so 5 days a week I don't have much control over it.