Easy enough to find flights I would think but you would have to do the thai livestock dept vet check no more than 5 days before your flight and of course adhere to whichever country’s pet import rules are in place as well as perhaps having to go through the same in that country to leave again, so import, then export requirements. The DLD (Department of Livestock Development has the import requirements of all countries on their website. I would stick with the country with the easiest requirements. Maybe Cambodia but again, not sure which airline will allow in cabin and Cambodia is probably not easy right now. I think Vietnam has one that does allow in cabin. You can also drive easily back and forth across the border into Laos with your dog (at least this is what I hear).