KVS Availability Tool is showing CO50 on 11/30 (R9) and CO51 on 12/5 (R2), so you should be able to get the upgrade to BF at ticketing.

Edit: CO46 (IAH-FRA) on 11/30 and 12/1 and CO47 (FRA-IAH) on 12/5 and 12/6 all show R0, so you are better off to connect thru EWR.