would like to give it a "dry run" on the ground before the flight
Why not see how long you can go without a smoke. Every night you go 7-9 hours while you are sleeping. Start with that during the day, see if you can work up to the flight duration +2 hours. Not easy, I know, but you can do it.
I wont bore you with all the good reasons why you should quit. You have heard them all before. But just try ... We'll be cheering for you!