My father just came back from Cuba. They are encouraged to bring a 20lb bag of tooth-brushes, toothpaste, clothes, toilet paper - and other items because Cubans cannot afford them.
It's a real stretch of the imagination to suppose that Cubans are doing anything, realistically in this area.
'Longevity' is not in any way a measure of the quality of healthcare - and 'infant mortality' is not so much a function of the sophistication of the healthcare system. Any nation with any civic control can achieve relatively low rates of infant mortality with clean water, reasonably informed doctors, antibiotics and some degree of pre-natal care. It does not take cutting edge healthcare system.
Again - the monthly salary of doctors in Cuba is $25. Please don't even begin to talk about anything until you address that point. Can you tell me how many functional CT scanners they have in Cuba? They have one for Fidel & Co. but the economics of it imply the number is de-facto 0. Anything but the most basic medical equipment is out of bounds for Cuban doctors.
Second - when Cubans send doctors abroad for training, and for 'aid' purposes, they do so whilst holding the doctors family members hostage, given the possibility for defection. If aid agencies pay said cuban doctors $1K/month - Fidel & Co. grab 99% of it, and leave the doctor with their $25 a month.
There is absolutely no preponderance of Canadians going to Cuba for medical care.
When Canadians 'really need healthcare' - they go to the US.
This, not including a) plastic surgery and b) middle class types who want otherwise very expensive surgery. But even in those cases, it's very rare.