Goal: Get a list of ALL sign-in activity, for the purpose of discovering inactive accounts.
Using Office365 Portal Reports, Azure Portal reports all seem to have a limit going back 30 or 180 days.
I assumed programaticaly using the API would not have the same restrictions, however it still seems i cannot look for activity older then 30 days..
How do i get sign-in/activity data for users who have not signed in for 180+ days
How do i get ALL, everything, everyone, ALL sign-in activity?
You can't - the service will only keep them for a set time, depending on the licenses you have. If you need more than that, you either have to export/store them or use a third-party tools that does this (usually cheaper than getting E5/ASM).