Much of the inventory that you can book through hotel loyalty programs with points is for standard rooms. It follows, that you can run into a problem when booking with points if standard rooms at the hotel are sold out.
However, don’t be so quickly discouraged when you are looking to book a hotel stay with reward points, and your search results come up as “the room is not available on points. ” It is possible that only one night during your range is not available on points (i.e. because the standard room is sold out) and that is what makes the entire stay unavailable on a given hotel loyalty program website.
Check each night individually online or call up the rewards program and inquire about each night. (Don’t forget, generally I always recommend calling if you can’t get what you want online anyway.) If it turns out just 1 or 2 nights during your stay are unavailable on points, you likely have the option of booking those nights that are available on points and the other nights with $. The phone representative can usually link the bookings so that you are booking just one room. I just did this when I booked my Marriott hotel in St. Petersburg for Jessie’s 2016 swim meet.
You can frequently check back online or via phone to see if those dates open up on points. That is what I plan to do with the St. Pete stay!