Canadian here, looking for the easiest( visa wise) way of spending 5 1/2 to 6 months in Thailand. TIA

Good day everyone,

Just bought my flight to Chiang Mai for January and just about to apply for a visa in Montreal, Canada, my home country. I was planning on staying in Thailand for at least a year on a METV (3 x 60 days plus 30 day extension) and then get SETV from Vientiane.

Now... I may have to come back to Canada to sell my house in July and stay in Canada for a little while so here's my question...

If I leave Thailand after 2 times 90 days, how long do I have before the third entry is no longer valid?

Thank you in advance