Our flight around Thanksgiving (four months in the future) was cancelled and we were rebooked on the exact same flight, 24 hours later. This will require an additional night's lodging as well as meals. Does anyone have experience being reimbursed for this, as the expense is unforeseen from our original plans. If so, any idea of what they would consider reasonable? For three people, our AirBNB in Rome would be another $700 for another night.

From the KLM website:

"Unforeseen expenses​

If you had unforeseen expenses because of a delay or cancellation, such as extra costs for a lunch or a phone call, you can request a reimbursement."