For sure this. But also, a few points for folks who believe this is due to "small population" or "low density."

1. Atlantic Canada has 2.5 million people. Toronto (city, not metro) about 3 million. Toronto had 381 new cases yesterday. Atl Can, zero. It's not about population. https://twitter.com/scottstirrett/status/1310576478229336065

2. A bit academic, but PEI and NS are the most densely populated provinces in Canada. They're full of small but fairly urban-scaled towns and small cities, with a lot of travel in-between, occupying a small provincial land area, with relatively little unpopulated hinterland.

3. Halifax is an urban centre of half a million. Its density is greater than many cities seeing much more infection. (Don't bother looking up official stats; Halifax's weirdly enormous metro area skews density to near-zero. But in terms of where people actually live, dense-ish.)

4. All the above aside, density has already been shown as a minor factor (or even a non-factor) in this pandemic. So forget about density! This is about overcrowding, social interaction, etc. Not how many people live within a particular square kilometre. https://www.jhsph.edu/news/news-releases/2020/urban-density-not-linked-to-higher-coronavirus-infection-rates-and-is-linked-to-lower-covid-19-death-rates.html

(Lastly, we shouldn't get too back-patty about this, IMO. We've been responsible, but I don't think any moreso than most. We just had good timing. Our initial lockdown quashed what was already a low infection rate, and then we told everyone to stay away.)