https://www.computerworld.com/article/3207547/office-software/what-happens-when-an-office-365-subscription-expires.html 


This is what occurs when Office 365 is cancelled - in case we are dealing with hosting by someone else. 


1-30 days after non payment, this is a grace period where things are still running but you will receive notifications about there being an issue with the Office365 subscription.

31 days after non payment, applications are no longer able to be accessed./

121 days after non payment - all data is removed from the account.