I biked in SE Asia on my Bike Friday folder with 20 inch diameter wheels--and met 4 other cyclists in Laos touring on Bike Friday folders, as well. The roads in Thailand are good. The roads I was on in Laos were mostly excellent, but a couple were not great. I wouldn't worry so much about wheels unless you're going off-road. If you do head to SE Asia, I would urge you to get away occasionally from the Mekong valley, because there are some great places away from the river. For example, Luang Prabang (Laos), and the fantastic but challenging road between Luang Prabang and Vang Vieng.