In a case like this, once a traveller has left Canada and their provincial MSP (or OHIP in Ontario) coverage has ended, then there are three options for coverage:
Starting with the least expensive option: a traveler may find coverage by contacting an insurance agent in the country they are travelling in. So, just like Canadian companies sell 'Visitors to Canada' insurance for international travelers coming to Canada, or US companies sell 'Visitors insurance' for non US residents coming into the US, a Canadian traveler may find a
UK company to provide the insurance if they are in the UK, etc. Issues: 1) if travelling through several countries, this is usually not an adequate option; 2) if the country in question doesn't have a strong regulatory process, the foriegn insurance company might not be that reliable at claim time; 3) these policies usually only cover emergency injuries or illnesses - not coverage for chronic conditions or annual checkups, etc.
The next option for a Canadian traveler, is to buy an Expatriate policy from a Canadian Company. This can often be cheaper than retaining and paying for MSP coverage while travelling on a normal travel insurance policy - depending on the age of traveler. Canadians (in Canada or already abroad) can find their expatriate insurance options here (sorry a link wasn't allowed to be posted - you'll have to cut and paste behind the triple w!) (new user) bestquotetravelinsurance.ca/expatriate-insurance-and-travel-insurance-for-backpackers by getting a quote (green quote request form) online and reviewing displayed info. (When I used to travel, 'spam was in a can')
The third option, is to buy an international expatriate plan from a (non-Canadian) company that will offer insurance to anyone, anywhere, anytime. Of course, all insurance policies have rules for eligibility, and provide a list of exclusions in terms of what is not covered, and all policies offer different coverage. In general though, expatriate policies are meant to act as primary insurance because they assume no other coverage is in place. So, they will sometimes even offer coverage for chronic conditions (or, that is, conditions that become chronic) and/or regular checkups. One of the more flexible policies out there in this regard, can also be found at BestQuote's site, down at the bottom of the page....