Freezing/Preserving an Excel Data Model & its overlaying Reports/Summary-Analysis/Insights

As suggested in the title, I am wanting to freeze (or preserve) an Excel Data Model (& its overlaying Reports/Summary-Analysis/Insights).

Reason why I want to do this: my organization's Reports are created using an Excel Data Model (that has multiple connections/integrations with its SharePoint Drive for its data sources) and I need to preserve this Excel Data Model (at reporting time) for record keeping purposes and to share outside my organization (to those who do not have access privileges to the underlying data sources).

The underlying data sources in SharePoint are continually changing and updating. So the reports tend to fluctuate one month to the next as issues are identified/corrected/refined. I want to have/retain a snapshot of what my Excel Model showed at each reporting event.

I don't fancy copy/pasting values, as this is manual and makes it difficult to interrogate/follow information flows; should an issue be later identified.

I would have thought this is a pretty common requirement, but I cannot find a solution from my googling... I presume this is due to wrong terminology.

What is everyone else doing?

If I'm going down the wrong path or there is a better place I should look for a solution - please say so!