Disable old user automatically/reclaim license after X days/months based on 'Last Activity'

Users login and create their own account but the Collaborator IT support team has to clean up old users with an 'Active' license quarterly or monthly depending on the hiring phase we are in.  In a largely distributed IT shop, a user admin team would be the team to provision.

It would be great if the system could disable Normal Users if their 'Last Activity' was over X days/months.

Preferably by months, like 3 months (or convert to a day value).  Administrator users would be exempt from the disable process.

Alternatively, being able to provision or un-provision using an AD group would be much more preferable but above would solve a provisioning issue we currently are faced with.