It was at least 6 months out, if not longer when I started looking for rooms at the Thalasso. I was hoping to just get 3 nights, with anything more than that as a bonus. I was ecstatic when I ended up with all 6 nights about 3 weeks out from departure.
I originally had 2 nights booked at the Hilton as well, but we end up having to change the date and the availability wasn't there for redeeming the free night certs.