So just to add in case you not aware that there is no such thing as fiancé sponsorship, you either have to be common law, cohabiting for 12 plus months or married.
In theory as a citizen provided you meet either the common law or married criteria you could start the sponsorship process from outside of Canada as long as you show intent to move back. To this end does make sense given a spouse sponsorship can take up to 12 months to apply maybe during your last 12 months of your current job outside the country.
Not sure from your post whether you meant you had the opportunity , past tense, or you have an upcoming opportunity Working abroad for 6 years, if the latter that would complicate intent to return to a Canada.
Ultimately once the spouse PR has been granted then suspect people might just spend as little time as possible in the country before leaving again and taking advantage of PR accompanying a citizen abroad rule for the PR to maintain residency obligation.