Multiple pages protected by different passwords. Possible to track multiple passwords at a time?

Rather than changing passwords on the posts/pages themselves, you could reset the users’ passwords every month. You would set up your posts/pages/CPTs such that only logged-in users of a certain role could view the pages you want to protect, assign everyone that role, and email them their monthly password. That way, when they try to view a page, they’re sent over to the login form; they must enter the current password to view any of the pages; and once they’re logged in they can view all the protected content.