Workload of PhD in US/Europe/Canada
I can provide some information about the US, and maybe a bit of perspective.

First note that the process of doctoral education is quite different in the US and parts (at least) of Europe. I'll focus mostly on things such as CS and mathematics. It may be different in other fields. 

In the US, there is a relatively low bar for acceptance into a doctoral program. An undergraduate degree is all that is normally required, though some institutions may expect more. Not only that, but a four year undergrad program in the US is a generalist degree, not a specialist one. The "major" subject is between 1/3 and 1/2 of the total coursework and not every student is much exposed to research. 

Moreover, most doctoral students in the US in these fields are, in a sense, self funded, as they are employed by the university mostly as TAs (sometimes RAs). Universities with doctoral programs in math and CS, also normally teach a lot of undergrad students, which means either lots of small classes or larger classes with lots of TAs. There aren't normally enough regular faculty to teach all of the courses, so they depend on doctoral students to help. 

In Europe, I suspect that the bar is higher for entry, with more courses and research experience expected. I also suspect that doctoral education there is somewhat less dependent on student teachers and assistants. In some places, doctoral students are regular employees, and may, therefore, also be teachers. 

But, I think you need to expect that no matter where you are, that doctoral education is a full time endeavor. You can "have a life" with outside interests, but your full time "job" is directed toward your degree. The exception would be for someone who can do a degree part time on their own funding. These are rare. And, I think that "full time" normally means more than 40 hours per week. Most people make sacrifices in that way and require that other family members are willing to accept that. It isn't so much that it is demanded of you, though it might be, but that research isn't a regularized process. There is no way to say that in X course I will achieve Y results. Insight is precious. 

Whether the "time to degree" differs depends on how you measure it. From the end of a secondary education to a doctorate is likely about the same anywhere. There are things that need to be learned and research that needs to be done and reported. Whether you count that as part of a specialized undergraduate degree, or an MS degree, or doctoral education, matters little. Since the starting point is about the same, and the end point is about the same, there are few shortcuts. 

So, what is best for you, depends on where you currently are. If you have the prerequisites done for specialized research, then you want a program that will let you get to it. Otherwise you want something that will help you reach that point. 

I'll note, however, that, even in the US, if you are well prepared on entry, many doctoral programs will expedite your entry into research without a lot of course preliminaries. You need to pass exams and write a dissertation. You won't, most likely, be expected to repeat courses for which you are already well prepared, though you may need a way to demonstrate your competence. You will need funding, and, as an international student, few fellowships will be open to you. So you will probably be expected to teach or TA. If you are already an experienced teacher, you may have more advanced duties than most, but (student) visa restrictions can still get in the way.