I just got this squared away with Radisson Martinique. They had standard rooms for purchase but not redemption. I called, had to be transferred a few times, but eventually got to the right person (Andrew is who I spoke with, in lieu of Denise [Dir of Reservation]). He referred to capacity control for redemption. I reminded him of CC's policy of "no blackout dates." Eventually he agreed. He needed to call CC on my behalf to make the booking. Took about 30 minutes total.
They actually had availability the weekend before and the one after (by that I mean redeemable online), so the overall availability seems OK (based on limited data).
Thanks to Mommy Points and the information here.