Microsoft is offering 100GB of free OneDrive storage for 2 years if you subscribed to Bing Rewards or were an existing subscriber. Sadly, Bing Rewards is not available in many countries but you still can get that free storage.
Just follow this link, login to your Microsoft account and accept the permissions prompt. After you accept that, your account storage will be upgraded immediately.
You don’t need to be in the US or use a VPN to claim the free storage. This worked for me and my account if from Mexico. I read that it’s working for users from Germany and other countries as well.
The free storage is good for 2 years but by that time perhaps the free tier of OneDrive will have as much storage if not more.