Already had a CBR standard room booked for 5 nights in mid December with base tickets. FD was available online, but I had to add the qualifying park hopper tickets to get the dining offer. When I went to change my reservation, the add-on costs to get FD came out to $425 for 2 adults and one small child spending four days at the resort. We REALLY want to stay at CBR this time, so dropping to another, less expensive resort isn't an option.
Since we were originally going to pay for meals out of pocket (dining plans tend to give us more food than we want), we can just about get all the meals we want for the cost of upgrading to FD. I'll wait till summer and see if WDW extends the RO offer past November.
Research on this thread has been very useful!