Did anyone ask:
Who is financing these Canadian purchases? Canadian banks restrict the amount of leverage, but US banks are more ‘generous’ on their leverage.

If the properties are being purchased by Canadians, using US Banks, we could be looking at R.E. collapse #2. Foreigners have a greater incentive to just walk away if the deal goes bad, particularly if they are highly leveraged. Now who makes the US Banks whole? Will they be expecting bailout #n+1?