don't know about flight options, hope someone who knows better can advise you.
but if you want to do it by bus, Nakhonchai Air bus company has an overnight VIP bus from Ubon Ratchathani to Chiangmai. according to their website (http://www.nca.co.th/newweb/index.php, Thai only), departs 17:15 & arrives 08:55. supposedly one of the more reputable companies (in terms of road safety) around.
I think that the "best" way would be to take a bus to either Khon Kaen or Udon Thani, spend the night, and then head to CM the next day.
I'm only suggesting this because the food in both UT and KK is simply outstanding! I'm thinking with my stomach here.
But it also breaks up the trip. If you're in a hurry, do the long-haul or fly.
Thanks for the suggestions.
I like the idea of going via Khon Kaen or Udon Thani, I am listening with my stomach!
#5 mrnoxious has been a member since 4/2/2009. Posts: 11
Hi Mr. Noxious,
KK is probably a better route to go by, though it is only about 4 or 5 hours from Ubon. It will give you a better route to Phitsanulok and then north than Udon Thani would. Udon Thani is a bit too far north.
If you do decide to go by this route, let me know and I can recommend a decent place to stay in that's close to the bus station.