Hoi,
Data of a national statistics organisation is by definition TOO much. My recommendation would be to give it initial focus on something basic, something like the number of inhabitants of municipalities. Another thing that a statistics bureau is good for is for using it as a source. When data in Wikidata can be sourced to a statistics organisation, it would be wonderful to be able to link to the source and compare and update.
When you start simple and focus on core functionality, it is easy to have it grow rapidly.
I am happy to talk with the people of the CBS ... <grin> it helps that I speak Dutch and double Dutch </grin>
thanks,
GerardM