The Canadian government has just announced a great protection for international students! As I write today, April 8, 2020, for any student who already has a work permit but can only take on-line courses from her home country, these courses will count towards getting a post-graduation work permit in Canada.
If your in-class courses are being moved to an online-only format because of COVID-19, your eligibility for the Post-Graduation Work Permit (PGWP) Program won’t be affected. This includes students who have a study permit or who have been approved for a study permit for a program starting in May or June but who are unable to travel to Canada at this time due to travel restrictions. International students in this situation may begin their classes while outside Canada and may complete up to 50% of their program while outside Canada if they cannot travel to Canada sooner.
This quote comes from this official Canadian government link as it appears today, April 8, 2020:
It is too early to say what will happen for students with study permits for September. Possibly, students will be able to travel to Canada to take courses then. But if they cannot, and they have a study permit, there is a high chance, based on this announcement that their on-line studies before they come will count towards getting a post-graduation work permit.
Also note that to get a post-graduation work permit of 3 years the rules require 2 years of study which is usually equal to 4 semesters of 4 months (a four year degree in Canada is 16 full-time semesters of 4 months.).