You Can't use Canada's System anyway
First off they (Provincial Health Plans) only pay at Canada levels (and to be clear it is not a Canada system it is a province by province system) , so that won't be enough dough anyway to cover, say Clinica Abreu for anything serious.
Secondly after 90 days leaving the country for good (and a year meets that definition) you are not covered by provincial medicare at all. You can't expect them to cover non residents just because you used to live there.
So.........buy ex-pat out of country coverage which may or may not include evac insurance - since if you are evac'd and you go to your home province and you don't have any more medical coverage you wil have to pay for 90 days until you are a resident again, just like you would have to pay cash for medical care if you stayed in the DR. So buy insurance that could evac you to a place with BETTER medical coverage like Miami and will also PAY for it wehn you get there.
You can find quite a few expat medical insurance comapnies online, check they have a high claims paying ability rating, I think through Best.
There is one "society" ( I think set up as a co-op to avoid being regulated like an insurance company) that will evac you anywehre you want if you are hospitalized at all ( other than minor things like getting a broken leg set, etc.) for quite a fair price per year, with no medical exam - here's a link, maybe research that, but if you are paying for a full evac included policy it may be redundant. It would be good though if you travel a lot to foregin lands and STILL have home coverage and you need to get home in an air ambulance, pronto.
Link:
http://www.medjetassistance.com/