Thanks for your reply.
As in these days, it’s common for both partners to have their own career in different places. This is our case. I’m a citizen based in Canada while my partner based overseas. So I visit and live with my partner for a few months each year, while maintaining resident status. It’s really confusing for us to answer if currently living together or not.
I understand, and I don't think it's that unusual or a problem generally but see below note about PR-sponsors. Just explain as briefly and factually as you can. [edit - just noticed you are a citizen - ignore that stuff for your purposes]
Personally I think it will make more sense to show that you are residing in Canada, and hence you do not live together full time, but that you spend 4-5 months a year together at her residence. The difference being that if you claim that you do live together full time, you are implying that you don't reside in Canada (even if resident in Canada in most other senses - note there is no single definition of residence in Canada, provinces and govt have different tests for different purposes). I think it's more clear to just say you live in Canada and visit your wife often.
It should not be a problem [as you are a citizen]. Note though that for PR-sponsors, you must be resident in Canada throughout the process and in-country when applying. The dept guidelines state "short trips" abroad are acceptable. They can cancel your app if they wish if you are abroad longer; no definition of what short trips means - held often to mean less than a month. It's unclear how actively they enforce this. But it would be in the interests of PR sponsors to limit trips abroad during the sponsorship as there is a risk they could cancel the app.
Repeat, for citizens, not an issue.