Moisheh: Ontario and BC allow 7 months out of Canada to keep provincial plan. Alberta still has 6 months, IIRC. This pretty much covers most of the country population. The caveat is the social pension (GIS) that won't allow absence from Canada more than 6 months in row. That is, for those whose income is low enough to receive GIS.
Oh, I've seen IMSS facilities alright. Scary. Public Hospitals (for Seguro) are better in big towns, but .... you have to be near that big town. Think 500 thousand people or bigger.
Talleyho69 - the Q about Zihutanejo was neither answered precisely, nor did it turn into he said/she said, because there was nobody with personal experience to tell, so far. There was enough info on the subject, though. The OP was planning "this" visit to Zihutanejo. With an added interest to use Mex public healthcare during his stay both there, and in other unspecified places in future. The smaller they are, the worse is the public healthcare. Zihutanejo is what - 50K population? Enough said...