As long as you're not cancelling days in advance citing the hurricane, I think you'll be fine. If it's days in advance, you might be considered playing the system. But given the hurricane it might be ok.

If it's ugly the morning you fly out, call the hotel (as well as the airline). If things are being cancelled, they'll probably work w/ you. If not, cancel anyway & then write Bill Marriott citing the hurricane. Best case a credit, worst case a future night (which they might be more willing to do).

Good luck - and be glad you weren't in Peru!

Cheers.