I always do #1 when I fly to SE Asia. I prefer late afternoon departure, cause my kid will wake up when we board (noise, sitting upright...etc). And then he'll get too excited to go back to sleep. Worse off, if my kid was woken up and cranky, everyone hated us at 2:30am.

When we depart in the afternoon, I'll make sure he gets plenty of exercise in the morning and at the airport. He may get a quick nap on the way to airport. Then food, TV on board for couple of hours, and crash at 8pm regular time. And we may get lucky that he'll sleep all the way to destination.

So it really depends on your kid. Do you want him/ her to stay awake in the beginning of the trip, or towards the end?