Big learning: never just have a root account on AWS, even if you are am occasional user one-man-show.
Apparently individual IAM user accounts can log in through region-specific management consoles like eu-west-1.console.aws.amazon.com, eu-central-1.console.aws.amazon.com etc
While all root account login requests get redirected to us-east-1, the only region that handles root login requests, which is also the region affected by the outage.