Flight canceled (IDB?) & compensation advice

Hello fellow FT'ers,

My flight back home was cancelled tonight, so I'm overnighting in ORD.

They gave me the pink slip for accommodations (pretty good prices, I guess) and I was automatically rebooked for tomorrow morning.

If I'm looking for the best compensation, what should I do and NOT do? I.e. can I jeopardize anything by talking the discounted hotel rate? Should I give them a call first (although I liv by the motto of "don't call the company"?

Thanks in advance for any hint.