It doesn't look good.

I see nothing at the saver level for NYC-BKK. There is a Saver seat in Y on REP-ICN that night but connecting past that isn't there. I didn't even bother with LAS-NYC.

Above searches were based off the availability shown on NWA.com. It is generally very reliable for what KE, DL and NW have as actual inventory. I didn't look into CZ; I think you'd need to call for that.