I think trying to book a month or so before your actual stay is gonna be difficult/impossible using a free night cert. I have 5 of these certs from Merrill as well and had no problem booking 3 nights at the San Fran Ritz in mid July. Unfortunately the certs are only good for the standard rooms and not the Club level rooms. I called the hotel and they said they might let me pay the difference to upgrade to the club level, depending on availability at time of check-in.