Having lived in Chiangmai for over 25 years, I’d say it all depends on your concerns—and your family’s.
You: During the worst days of the smoky season, staying indoors with the air conditioner and an air purifier solves most of the problem. But yes, it's not fun. If you're still working, it depends on your office environment. I keep an air purifier at work, just in case.
Your family/wife: If she works, she'll face the same issues as you. If she doesn't care, then you might have a problem.
Kids: Some schools have air conditioning, some have air purifiers, some change the filters when they're full, and some even remember to turn the purifiers on 😉. They rarely close, and they won’t cancel Sports Day—even if it’s smoky—because hey, the kids are wearing masks anyway!
The biggest issue I face is the typical “mai pen rai” (never mind) attitude. For example, coming home to find all the windows wide open while the air purifiers are running shows the problem isn’t really understood—or taken seriously. But... This Is Thailand (TIT).
If you're open to traveling down south—really south, like Surat Thani or further—during the bad weeks or months, and you’re fine enjoying a quiet life alone or with your wife, that could be a good option. This year though, even places like Hua Hin and Bangkok have had quite a few bad days, so it’s not an easy choice.
If you plan to stay here year-round, the smoke and how it’s handled can definitely be a challenge. Good luck!