If you are leaving from the U.S. for Bangkok and you are traveling between December and April or May, some of the best airline deals for business class are the day after Thanksgiving and that weekend. I tracked the prices daily of several airlines from the Middle East and China for several months before. Ended up with Turkish Air out of New York for March, 2017 for $2000 - a one day sale the day after Thanksgiving. I prefer Emirates or Etihad, but could not resist that price. The year before, Etihad had a sale that was not quite as good on an A380. Very memorable.
Up until a few years ago, I used to fly economy, but this delicate body has seen better days and has a difficult time for so many hours and time changes. I would rather spend the money on the flight, arrive in good condition, and than save on hotels (but not on entertainment!). I very much like Vinapu's advice on hotels and on leisure time activities!