If it might be helpful to others, here is KLM's twitter response regarding compensation, which does not commit to any specific compensation, only that it will be considered.

My message: "Specifically in reference to our return KLM flight on November 29, which has been cancelled and rebooked for 24 hours later, requiring an additional overnight stay and meal expenses. Please provide clarification that your Unforeseen Expenses policy will cover an extended night in our AirBNB in Rome, which is approximately $700USD, plus meal expenses?"

KLM's twitter response: "I can understand that this was not how you expected your journey to go. Please note that submitting a request does not guarantee that you will be granted compensation. Rest assured that your request will be reviewed individually and carefully."