@Lisa F you chose the wrong ppl to ask... like everyone else here, I moved my trip a little earlier. I was initially supposed to go on Dec1, then it was Nov30 8pm flight which got us in around midnight, then I moved it to Nov 30 10am wherein I had to book an extra vacation day from work!
Seriously though, I think it's ok as long as your son can handle it. If you get up that early though, I'd still be prepared for an early night. My first day plan (w/ us waking up at around 5am still since its considered a intl flight) is just to see Xmas decors around the universal resorts and walk around city walk. No parks.