Also have unlimited mobile data plan with AIS for $20/month, which is really surprisingly fast given what you're paying.
Thailand's been an eye opener on many levels, will definitely be heading back here next winter if I'm able to.
This channel has some pretty decent vids on the subject
https://www.youtube.com/channel/UCmnpMr4Md5CgZ5MdlghTYqA/vid...
Bear in mind though that Chiang Mai is more of a rural town than major city, you might find yourself preferring Bangkok.
The only real gotcha is now, when the "burning season" begins. Farmers across the north of India and SE Asia start torching previous season's fields, which leads to poor air quality. Up until February you're basically good, it's after that that you start seeing people (myself included) donning the wearable breathing masks.
Here's how things are now, just look at all that fresh air[1], you'd think the earth was a tail pipe.
[1] http://berkeleyearth.org/air-quality-real-time-map/?z=4&x=10...
http://www.ais.co.th/fibre/en/
You can see some of the services available there.