That's a strange answer above, I don't see how the OP can rebook anything without the airline being involved. But airlines are only proactive with their very best customers and even then, not always.

So the instant you find out your flight has been canceled, you should start looking for alternatives on your own. Ideally they will be on the same airline but you should have alternatives on other carriers as well.

Having done that, you can then contact the airline and not be pushed into an inconvenient alternative. Maybe Ryanair would tell you to pound sand, but KLM should be more accommodating.