I am a Canadian PR and my fiance is in India with no current Canadian status.
In July, she applied for her TRV as a single/unmarried person who wishes to visit me (her friend) in Canada. We attached travel itineraries and tentative travel dates, and also mentioned in the letter of explanation that we understand that immediate travel may not be possible, but since this visa is usually for 10 years, we are applying now. And we attached all necessary documentation.
On Nov 2, we got married and after marriage, I submitted a webform and also wrote to the IRCC travel exemption email ID that we now qualify under immediate family reunification and supported the email and webform with documents to show strong ties to India. A statement showing her net worth in India, her employment contract, etc.
Although spouses are able to travel they must qualify for a TRV which is the hard part of the process. Many people misunderstood and thought that all spouses would get TRVs and be able to come to Canada. The obstacle remains getting approved for a TRV.