There is a bit more than just informing users: If you decide to go down this route, you should bear in mind that other supervisory authorities might be stricte

There is a bit more than just informing users: If you decide to go down this route, you should bear in mind that other supervisory authorities might be stricter and that you must be able to demonstrate that it’s impractical to delete backup data. This will require, at the very least, a risk assessment, business impact assessment and data protection impact assessment.