We have blocked a number of rooms at the Marriott in Tarrytown. If you plan on staying there, mention "Goldfarb/Siemaska wedding" when you call to make the reservation.
670 White Plains Road
Tarrytown, New York 10591
The hotel is about 30 minutes away from the wedding location by car.
(As we mentioned before, for anyone staying in NYC, it's a piece of cake to get back and forth via train and taxi.)