I have been taking ambien for years on overnight flights. It works wonders for getting sleep on the plane. I typically get 4-6 hours of sleep. I take it with dinner and wake up in time for breakfast. Never had any difficulty the next day.
I definitely agree with trying a dose before you travel. I need 10 mg (full dose) to get me to sleep. However I had a friend who took 10 mg and reports that her travelling partner had to drag her through Paris customs.
She barely remembers anything until she got to the hotel.
I would suggest starting with 1/3 or 1/2 tablet the first time. Since it works quickly you can always take an additional 1/2 in 20-30 minutes.