I could actually see CFB being played and the NFL not.
Think about it, most CFB players don't have a spouse and kids and are already away from their primary family for a few months while they are away at school. It COULD be possible to essentially quarantine entire teams and coaches and have them play games with no fans.
With that said, there are a myriad of "what ifs" and immense hurdles (eg a player on a team tests positive, is that team "out"? - Think about if a player tested positive right before a game, is that a forfeit for the season??). If CFB was the only sport, then I'd guess that the TV revenue would surpass the amount of lost ticket sale money.
My guess is that it will be an all or nothing for P5 conferences, and likely CFB as a whole. Look at what happened with CBB conference tourneys and the poor optics that a conference/school could face.