Hi Kawabunga,
We are exactly in the same boat. My wife and I applied as common law originally.
My wife and I got married in June, we got PPR on July 12th.
I informed CIC thru a CSE on July 13th about our marriage.
CIC send me spouse kit thru MyCIC on July 14th for me to complete: 9 more forms to fill out and my wife needs to be reassessed as a spouse instead of partner! Meaning it could potentially take another 3-6 month!
I email local PM about the concern and raised another CSE about the redundant work: we were already approved as common law partner, why reassess her?!!!
After a lot of back and forth, CIC took back the kit and the wait began....
Now it's been 3 weeks, I get no reply from CIC, no update, my original PPR is no longer valid.
My recommendation: Before you land, you can go ahead to get married ceremonially, but do NOT get certificate or change your wife's name. ONLY get legally married or change name after landing. LAND AS HOW YOUR APPLIED, and DON'T TRY TO LIE ABOUT YOUR MARITAL STATUS(even if it's just common law vs married.).
You will thank me for following my advice.