If you are going to book a flight directly to Edmonton, then you will land at Edmonton Airport obviously, that is your point of entry and that is where you will get your Work permit print out.
It does not matter what time...morning, afternoon, evening or dawn....There will be somebody there at the airport to print your work permit.
Now if you land to Vancouver first, then that is where you will get your work permit because that is your POE. then you will catch your connecting flight going to Edmonton. They might check your work permit in Edmonton airport just to make sure you went through the right process...
get it?