When subscribing to Office 365, you get a number of licenses, but you can't really use them without signing out and back into another account, and even then it's a pain because the directory would be the same.
You could use them for storage/backups though by starting a Windows Sandbox and using it from there. I created email accounts that matched the use so I could remember what was where. Yes yes I know harddrives are cheap, but you shouldn't really store your backups at your house.