Other Flex game options: Vikings-Bengals Bears-Browns Steelers-Colts Falcons-Colts
All of these games are labeled as flex games for 12/16 or 12/17. Not sure if there is a Saturday night game on 12/16, but the rest of the options seem like bad options.
It can be flexed into the normal Sunday 1:00, SNF, or any of the three games on Saturday