Changing Reserved EC2 Instance Region

Hello Ren,

Amazon EC2 Reserved Instances are subject to modification.[1]
However, First, check the conditions listed at Requirements and restrictions for modification. If your Reserved Instance meets the conditions, you can request to modify the following:

• Availability Zone
• Scope
• Instance size
• Network platform

According to the above conditions, "Region" can't be modified.
I think you can contact AWS Support with providing your RI Lease ID to see if you can cancel your Amazon EC2 Reserved Instance.

Hope you will find this information useful. Please let me know if you have any further questions or concerns. I will be more than glad to assist you.

Best regards,
Jisoo K.