Chiang Mai and the rest of Thailand are rather shit at the moment with insane entry requirements. Even if you persevere (and don't get jailed in quarantine hotel) understand that there are no tourists, no expats, no nightlife at the moment and many many failed businesses and ghost town vibes.
"Just learn Thai lol" is not actionable advice either. I say this as someone who has literally done what you suggest in 50+ countries. If he could somehow sneak into New Zealand (not Australia!) I'd strongly recommend that instead at the moment. Buy a van. Hike. So many great treks and places that you usually need to reserve months in advance and far higher likelihood of meaningful interactions.