Hi,
First of all, you must decide for yourself about how certain you are that your status will change.
There is no point telling your VO that you are likely to get married.
You basically have 2 options:
i. Postpone your marriage. Get COPR, do your landing and later sponsor your wife. This option will mean that you will avoid delays now, but a lot of delays later, as spousal sponsorship takes a lot of time.
ii. Get married and notify VO of the status change with relevant docs. These docs will be marriage certificate, police clearance for spouse and updated proof of funds. In addition, add some photographs of your marriage and reception. This option will mean that your file will go on hold while they verify information about your spouse and do background checks, medicals etc etc. But this delay is much better than the hassles of sponsorship later.
What you must not do:
Let's say you get PPR, send your passports and VISA is stamped. After this, in a month or two you get married. In this case, you must not land yourself without telling VO, because that will be misrepresentation and you will also not be able to sponsor your spouse later.
Bottom line : There is no point contacting VO with the likely and probable scenarios. However, you must update your VO the moment there is an actual change in your status before landing.