Medipac Travel Insurance is recommended by the Canadian Snowbird Association and the Canadian Legion as a supplier of travel medical insurance for Canadians. I have not used them.
Blue Cross travel insurance is available through its Ontario agent MacLellan Moffatt.
You should also look at what, if any, vaccinations you will need, and arrange to get them. The Government of Canada travel website has a list of suggested vaccinations by country. You can also contact your physician or local health unit.