The only thing I would like to add to the earlier part of my answer is a reminder that the two-step process still applies in terms of access to information in ministers' offices. If an institution could reasonably expect to have access to the information—for example, a deputy minister might have access to what's in a minister's office—and it applies to the work of the department, it is subject to the request and the system.
On October 18th, 2017. See this statement in context.