What's all this talk about Buffalo forfeiting games? Yes, this is incredibly tragic, even if he survives, and certainly many of the Bills player are no doubt traumatized, but there's no way they're forfeiting this game or any other game.
Firstly, is that how they're going to honor their teammate? By taking an L for the night. Secondly, the NFL would have to be pretty cold to slap an L on Buffalo even if they determine they're unable to continue with the game. I think the league would either discount the game entirely or conclude it as a tie. But really I doubt either happens because of the potential ramifications throughout the AFC standings.
Regarding their week 18 game, they're not forfeiting that one for sure. The league's just going to agree with handing the Patriots the 7th seed and eliminate several other teams? No way that's happening.
Seems like the most likely outcome is proceed with week 18 as scheduled, and once that's concluded, consider if the Bills-Bengals is even necessary (which it probably will be but there may be some scenario where the seeding is solidified), then possibly reschedule it for next Thursday, and push back by a day or two any resulting wild card games that either are involved in. Or have the Bills-Bengals play either 1/14 or 1/15 and push the playoffs back one week (which would condense the Super Bowl wait from two weeks to one).