score:4
You can make any changes you wish to your travel plans, with these caveats:
Upvote:2
We have anecdotal reports that some Schengen countries -- Czechia in particular comes to mind -- appear to have a policy of revoking visas after the traveler cancels the original hotel booking. (It doesn't look like Czech hotels have a duty to report cancellations, rather that the Czech consulates let themselves be used as a way for hoteliers to retaliate for the cancellation).
However, this doesn't seem to be usual for either Spain or the Netherlands.
The common Schengen rules allow a visa to be revoked "where it becomes evident that the conditions for issuing it are no longer met". But the rules do not specify in particular which facts can be interpreted in that way, so it is up to each member state's own procedures and administrative traditions how to implement that in practice.