I've done way too many long haul flights, the first to the uk when ds1 was 13 months.

We broke up that trip in Singapore which does help. I honestly don't think it makes much difference what time you go.... Whether they're ready for bed etc. as there are so many disturbances even before you get to the plane.

Once you get in there you can only take it as it comes. It's a long time in a confined space but you have to handle as best you can and IMO the best way to do that is without worrying about other people around you and focus on your dd and her well being.

Take things with you, toys, play dough, books and snacks. Walk around and maybe see if the flight isn't busy if you can have an extra seat to spread out a little. My guess is she might be too big for basinette but not old enough for her own seat.

Good luck with it all, you'll get through it in one piece