It's a long enough haul to Thailand to feel ghastly ill by the time you reach your first hotel, minimizing miles might not be the only consideration. (I worked through the feeling after 3 hours sleep to meet friends for a spectacular hot & sour fish noodle breakfast at a nearby market. This helped as it would have for a bad hangover, suggesting that the two conditions are not that different!)

Construct a complete list of partners for each airline on which you have sufficient miles, check out their reps and their blackout dates.

I only had sufficient miles on CO, when I went last Nov/Dec. EVA was blacked out, so I used 120,000 miles for Korean Air business class. This was an 'older' plane, as in I squirmed badly in my seat. If I had such a barca-lounger in my trailer, it would have ended up outside as yard art next to my broken-down cars! I think KE is also getting this message, the newer planes (out of LAX, on which there are no rewards) are apparently better.

If you can get EVA, I'd bet anything from comparing notes with fellow travellers that their Evergreen Class (fancy coach) is more comfortable than the biz seat I had on KE.

(I'm off SFO to CDG on CO in the morning. First time that far in coach in a very long time, but I need the miles to regain Plat.)