For me I will renew my passport now if I have the same passport validity period same as your wife. By the time the application process is about to finalized my passport will have short validiity period. Though you can choose to submit the PR application first before your wife renew the passport and just inform CIC the details of your wife renewed passport while your application is in process coz passport renewal from outside your own country takes nore than a month (depends by country) which can delay your application submission.