D.P.
I remember the nap heading South at about 3ish. That's when we switched to quiet time. He used to have approx 60 minutes in his room playing quietly, reading, puzzles or watching a DVD. Even though he NEVER slept, it did seem to "recharge" him to get through dinnertime. Also, play it by ear, if he's really tired and miserable, let him eat earlier if you can & put him to bed earlier. He can go to bed at 7:30. He MIGHT end up sleeping in longer in the morning, as a bonus.