@Ken *******
get an Non O for 90 days from his local Thai Embassy before he leaves Canada, this can be done online and he no longer needs to mail the passport. He'll get 90 days stamped in on arrival. In Thailand, with 30-45 days left on the entry stamp go to the Canadian Embassy or consulate and get the affidavit mentioned by Philip, just needs to provide his Proof of Income from CRA. Then go to immigration and get the year extension based on retirement. Once he is ready to head back and sell everything, he can easily get a re-entry permit at the local immigration or at Suvarnabhumi airport when he departs. We did this last fall and it's super easy. The Thai Consulate in Vancouver was really helpful in answering questions and the overall process. The Canadian Consulate in Chiang Mai was great to deal with in getter the affidavit.