I think there are some merchant areas in Chiang Mai which may be more receptive to Bitcoin payments. Name-drop incoming:

- Nimman (obviously); Wrap Master, Smoothie Blues, Beast Burger and Pizza, Free Bird Cafe, etc.

- West of the Ping river there's Blue Diamond, and I recall a night market on Changklan but I don't remember the name. Perhaps it's Ploen Ruedee.