Hi - just some sympathy as my 5 year old is a hyper at night too. We thought he wasn't tired as he shows no signs, no yawning, no getting cranky, still full on, but he was harder to wake up in the morning, wants to get into our bed at night and grumpier during the day. Also, he wet the bed once or twice which is a sign from him that he is in a very deep sleep - so OT. But, can't get him to sleep earlier - so what to do?
We worked out it was partly lighter evenings, partly a hangover from later nights during the holidays, partly jealousy of his older sister who stays up later, and just not needing so much sleep as when he was younger. We "fixed" it by getting him really tired one weekend, so he went straight to sleep. The next day - same thing, so the routine was restored. Also, moved bedtime back by an hour. (8pm). He doesn't sleep straight away when we leave the room, but he is quiet and doesn't get up.