Sure, just be a socialistic/communist government and be able to finance the pension system while depending on US money (because there isn't any good alternative), once you go too much into debt and deal with IMF, and be sure not to defund important services (like medicine) when they ask you causing bank runs and bankrupcy. Easy, no?
Oh, and make sure there is no corruption that would cause funds to be mismanaged.
Why the hell would they depend on US money if they become a socialistic/communist government that channels its GDP to its people instead of channeling it to tax breaks for the rich.
> corruption
No problem - they can just legalize it under the name 'lobbying' like how US did it.
Indirectly, because they depend on petroleum/oil/gas. Sure your glorious government has to import energy or other fuel derived products. Not to mention imports don't magically teleport to your location, they also depend on oil to get shipped.
> No problem - they can just legalize it
That's just papering over the issue. Akin to saying we solved drunk driving by setting alcohol in blood to 50%.
Lastly, Canada's population isn't shrinking. It's growing, thanks to a sensible immigration policy (well, mostly sensible; not recognizing the credentials of healthcare professionals is pretty dumb).
Public healthcare is only difficult to find when your government's priority is to personally engorge on a gravy train powered by corruption. All of the issues facing the Ontario healthcare system are intentionally self-inflicted.