Jomz is 100% correct. A Canadian citizen sponsor can reside outside Canada for the whole period of the sponsorship application AND may continue to reside outside Canada after the applicant has been granted PR status by "landing".
The ONLY requirement is that the Canadian citizen has to demonstrate an intent to return to Canada after, or at the same time as, the sponsored applicant has been "landed". This "intent" is not enforced but must be demonstrated as part of the application.
Finally, the applicant will have any days outside Canada, while accompanying their Canadian citizen partner, treated as "in Canada" days for PR residency purposes, but not for citizenship purposes.
The information provided by ANigerian is, unfortunately, erroneous..