I am another who uses the 1TB free storage that comes with EACH of the five users in my Office 365 subscription since I actually need over 2TB of cloud backup.
For circa £70 per annum for evergreen software and reliable offsite backup, this is as cheap as it gets. Here is how I have done it.
- Logged in to my wife's Office 365 user account via the online web portal
- Created a password secured folder using a name that includes reference to the account that is hosting it (this so I don't forget in future - no other reason)
- Shared the folder with my own Office 365 user account
- On my wife's laptop, opened the OneDrive app and stopped sync of the new folder since she only has a 120GB SSD
- Repeated the above steps using my son's Office 365 account
- Checked that all three folders (mine, my wife's and my son's) all appeared in my OneDrive folder - they did
- Used all three folders to check they worked, including backup and deletion to the Cloud - they did
- Purchased a 3TB HDD* and put it in a USB3 caddy
- Cloned to the new HDD my entire existing HDD that includes my OneDrive folders (at 1TB it was too small, and cloning was simply a File Explorer copy with "Show all files" enabled)
- Powered down the computer
- Swapped the 1TB HDD for the new 3TB HDD
- Powered up the computer and checked the new HDD was using the correct disk letter - it was
- Copied my files to the appropriate OneDrive folders according to how I decided to use them
- Success
*Western Digital Red series. Designed for NAS usage but work great in PCs and in my experience utterly reliable, decent performing, and low cost