Why are Canadian banks left unscathed?

Here is one MR reader request, from RW Rogers:

Is it true that Canadian financial institutions have been relatively unscathed by the recent worldwide economic turmoil and that they were relatively unscathed during the Great Depression? If yes, why?

The Great Depression is a straightforward story, here is an excerpt from Paul Kedrosky:

Despite being adjacent geographically and tightly connected economically, banks failed in Canada and the U.S. at very different rates. Specifically, no Canadian banks failed in the period, while more than 8,000 U.S. banks failed.

Why? Among other reasons is the different structure of the systems, with Canadian banks having a branch banking structuring, making them less tied to any specific region or customer. For their part U.S. banks in the period were larger in number but smaller in assets, with far more single-branch banks in the U.S. than in Canada (where there were virtually none). The larger branch network created resilience, not just in terms of assets but in terms of markets.

What about the noughties?  Nick Rowe makes some relevant points: Canada has fewer major banks and they are more tightly regulated, hold more capital, and housing is not encouraged so much by law.  It is harder to walk away from an underwater mortgage.  Here is Megan McArdle on Canada.  Simon Johnson explains why the Canadian model cannot work for the US.  Most significantly, the U.S. banking system is in part the Canadian banking system, not so much for deposits but for high-risk activities.  That makes Canadian banking look safer, but of course Canada as a country bears a lot of risk from when the U.S. banking system goes bad.