What about just having mirrors on other Git 'hosting services' / Git remotes - self-hosted ones and popular, known ones?
Although this is not a full solution but it could significantly reduce the risks of disrupting development and access to code BUT only as long as the different mirrors are hosted in jurisdictions that are separate. For example if both are located in US or any country that follows US (UK, Japan, South Korea,...) then it will only create false sense of security.