I've not seen this advertised anywhere, but right-clicking on my Onedrive icon on my Windows10 PC (bottom right, taskbar icon on the PC) and choosing "Upgrade", I was pleasantly surprised to see the Microsoft store offering a Free 1 year upgrade for Office 365 (2016 edition, Personal, includes Outlook/Word/XL/Publisher/PPt/Access/Onenote) and which also includes an additional 1TB of OneDrive cloud storage. Good to mid-August 2016.
You will need to gve card payment details but notthng is debited from the card.
I think this is only available for those not already subscribing to Office365 but having an unpaid subscription to Onedrive, but worth a try ? Ts & Cs state you need to be a OneDrive free plan subscriber without an existing paid OneDrive, Office 365 or Groove Music subscription, and have over 5 GB of content stored on OneDrive.
The personal edition will allow you to install on 1xPC/Laptop/large tablet, 1xsmall tablet (I think 7" or less), and 1x Windows10 phone.
Has worked OK for me and an extra 1024GB OneDrive storage added in addition to my current 30GB free allowance.
**Addendum** You can also turn off the auto-renew immediately by toggling the option under your "subscriptions" menu.
Now, you are then offered the option to auto-renew again with 1 extra month free, so you get an extra month free.........so 13 months altogether. Then you can still switch off the auto-renew leaving you with 13 months free access and the extra month remains.
This gives the deal the value of £5.99 x 13 months = £77.87.