What to wear for invited talk in Canada
Note: I am not Canadian, so this may be a bit off. However, I do hire post-docs fairly regularly into a research group at a US National Lab.
First - for an official post-doc interview your proposed attire seems appropriate. Dress slacks rather than jeans would be an upgrade, but probably not necessary. (Note that standards in the US can vary regionally, I'd assume similar in Canada. What is needed in Toronto might be different than Vancouver or Saskatchewan. An interview in New York City is different than Denver.)
As an added comment, you should treat this as a job interview because it definitely is one. While it may not be the formal interview, they have asked you are going out to give a talk. Any impressions from this visit will apply to a more formal interview. If it goes well, there may not even be a separate formal interview. Good luck.
I am Canadian and am at a Canadian university. However, I am in engineering, so your field may be different.
Here are some thoughts:
Business casual is usually acceptable for giving talks here, and I am in full agreement with Jon Custer's answer. I have been to many talks from visiting academics and other than when they are being formally interviewed I have never seen anyone wearing a suit.
Your chosen attire is perfectly fine, given (1) above.
It has been my experience that no one really pays attention to the speaker's dress. As long as the talk is engaging, business casual will be fine.
The vast majority of professors I've interacted with dress business casual, with some being more casual than business. Only very rarely do I work with someone who wears a tie, and then it is even more rare to see someone in a full suit.
Female, Canadian postdoc at a Canadian university here who was recently hired into a biomedicine lab after a job talk. I wore dress pants and a trendy button up shirt with trendy flats for my interview. FWIW, I would have felt very underdressed in jeans, but not overdressed with an additional blazer. What you've described fits perfectly with the academic culture I've experienced at three different institutions in Southern and Eastern Ontario. Good luck!