Very true re this earlier departure. Hope you enjoy your flight and post back how you get on if possible?

My strategy would be to get up very early on the day of departure, stay up and hopefully by 8pm IAH time you might be ready for a sleep.

That's what I used to do when going to the West coast USA as I liked the early flights back. It could also be my age on the wrong side of 50 and liking early nights as well as an afternoon nap