Well Big Harvey this is how I see your predicament.
KLM cannot operate any flights through no fault of their own therefore I think it highly unlikely that they would stand the cost of 7 nights in a hotel.
You therefore have 2 choices:
1. Take the financial hit on the chin and enjoy as best you can your enforced vacation.
2. Make a dash overland by bus, train and ferry. However, although the cost of doing this maybe offset by a refund on your unused return air ticket, it may not be as easy as it sounds as many hundreds of thousands of other passengers across Europe will be in a similar situation and if you set off right now, it is quite possible that it may take you longer than waiting for the next available flight.
I know which option I would choose.