I do not know, bro, really.
It is mentioned in PPR mail that vo should be informed about:
"Change in marital status, for example due to marriage, divorce, annulment or death"
Now, as you have already received PPR, you have got 30 days to submit the passport. As you said, in "upcoming months", you are going to get married. Technically, there is no change in marital status till you actually get married. So there is no meaning in informing right now.
Talking about future,
Even in an information sheet that comes with Visa, it is mentioned that if your marital status is changed after issuance of visa and before leaving Canada, you have to inform VO AND Return Back your Visa. If you fail to do so, you will NEVER be able to sponsor that unexamined family member. Now this is a serious consequence.
Solution as per my opinion:
Option 1: If you are getting married in a month or two, you may write an email or raise CSE regarding the same so that PPR could be kept on hold for couple of months, I guess. Meanwhile, you may execute Court Marriage.
Option 2: Let everything be as it is. Get the visa. Land in Canada. Get PR Card. Then after some months, come to India for marriage and Sponsor your wife. It takes 6 months or so, I guess, in the process. This is safer option. VO never asks for information of Fiancee.
Now choice is yours. Remember, I am not an immigration lawyer. So, I highly recommend you discuss this with your consultant or a good immigration lawyer.