A colleague and wife (both Blue and with really no status of any sort) on an MFU to NCW, had their evening flight out of JFK cancelled and were put on the next morning's flight.
They were offered nothing ....
With a little tutoring and only a couple of e-mails (highlighting the deficincies in BA's failure to honour the EU obligations), he scored the full EU compensation by cheque within a week for both of them, and about 6 weeks later he got all the NY out of pocket expenses (including a night at the Ritz Carlton) and 50k miles.
I think that is a pretty reasonable deal in all the circumstances.