Comment Re:Meh (Score 4, Insightful) 830
2x4s, of course, aren't 2" by 4". They're approximately 1,5 by 3,5 inches. As for lengths, here in Iceland it's sold in meters. We refer to our weights in kilograms and our heights in centimeters. Butter is sold in 500 gram bars. Cans and bottles of beer are in millilitres; I don't know what they call the size of a glass at a pub because I don't drink. Anyway, it's really hard to think of things we use imperial units on. The one that comes to mind is TVs, they're in inches. I'm sure there's others - they just don't come to mind at the moment.
The British are famously not-metric (they even use miles for distance), and Canada has a reputation for only being half switched over, so you picked two of the worst examples you could. I found this map which seems to be more detailed than a simple "metric: yes or no?", although I don't know what the color codes mean (red is clearly "effectively 100% metric").
And no, people will not "use whatever they are used to". They'll use what's on the package and all of the road signs. They're not going to pull out a calculator and start running conversions. You move to a metric country, you just get used to how things "feel". You don't need to know the conversion factor for miles to kilometers, you just get used to the fact that a kilometer is basically a "short mile" and the like. You get used to "0C = freezing, 10C = jacket weather / layers, 20C = light long sleeves, 30C = short sleeves" etc. You don't run conversions, you just get used to the norms.