(Sorry to chip in on an NZ issue but I guess the principle is universal)
One way to outlast the relentless lava lamp churn of national and regional health organisations and policy is to publish the content openly to an independent third party, for example put the content up on GitHub in simple MarkDown text form where it is easily adapted, improved, and curated by those with an interest (and there is a mechanism for accepting contributions from those outside the organisation - the ‘Pull Request’).
Changes of national organisation can have no effect on that repository, and it’s easy for regional organisations to work together on commonly needed content. From a public ‘master’ in version control it’s very easy to ‘syndicate’ this content out to other presentation layers eg websites, apps, PDFs, locally-branded versions, etc but the core content remains the same.