While Thailand is quite loose, lenient, and lacking in enforcement, days spent is not a big focus in Canada to determine tax residence. You can be Canadian tax resident simply by having residence available in Canada or other vague connections. Days spent is more of a last resort in Canada, for people who don't tick any other boxes but still spend 183 days in Canada.
The Canada,Thailand tax treaty defines residence as:
In your case, you are probably tax resident in both according︂ to this clause.
Just follow those clauses to figure out️ where you are tax resident. It wouldn't hurt to have a tax lawyer help you figure out where you would fall in your case.
Based spending 5.5 months per year in Canada, I can see Canada insisting you are tax resident there under a, b, and c, making it up to Thailand to fight for you to be tax resident there instead of Canada.
The term permanent home isn't defined in the treaty. But if you manage to spend 5.5 months in Canada, wherever you've been living might qualify as permanent. And if you're spending nearly equal amounts of time in both countries, it might︀ be hard to convince Canada you have your centre of vital interests in Thailand (why︁ don't you live there all the time if it's your centre?). This takes us to︂ clause 2(c) and habitual abode. We're probably back to 5.5 months being long enough time︃ in Canada that wherever you were staying before counts as a habitual abode.
In the︄ end, you're left with clause 2(d) to save you.