We are seeing nurse shortages in Canada as well. Mostly due to poor working conditions (long hours, no paid sick-leave in some jurisdictions). Some low staffing even attributed to evading forest fire smoke (anecdotal).
It's very hard to find the info in Canada. But, it would be interesting to see historical fluctuations in ICU capacity, how much spare capacity is maintained, and how much capacity is taken up by COVID patients.
A 2015 study found that critical-care capacity varied across Canada and should be addressed to avoid regional disruptions for spikes in need[1].
Healthcare systems were perhaps already stressed, and requiring adjustment and improvements, and COVID pushed them over the edge.
[1] https://ccforum.biomedcentral.com/articles/10.1186/s13054-01...