If you haven't booked it, don't book it. If you have, just gear yourself up for no sleep on the plane and an utterly wasted first day there. Because that is highly likely, and it's best to expect the worst so IF it doesn't happen, you can be extra pleased.
My son would not have slept on the plane at 2, and will not sleep on it at 7. Too much going on.
And since a parent can't sleep unless the children are, if there are kiddie sleep problems, you're up too.