Based on current scores here's my guess. Usually the "undesireable" game (i.e. AFC South) gets the Saturday 4:00 slot. The MNF game has been 4v5 last two years, which makes sense because it doesn't affect re-seeding, allowing them to set the divisional round schedule Sunday night. I'm guessing NBC will want the "better" Saturday game as the Peacock game to drive subscriptions, but that may also be a faulty assumption, that could be where the "worse" game gets dumped.
Sunday CBS/FOX games can flip timeslots as well. I think FOX gets the 4 PM matchup though, especially if the Cowboys are in it.
If Bills win:
Sat: Cleveland-Houston 4PM (NBC), Packers-Lions 8PM (Peacock)
Sun: Buffalo-Pittsburgh 1PM (CBS), Rams-Cowboys 4PM (FOX), Chiefs-Dolphins 8PM (NBC)
MNF: Bucs-Eagles
If Dolphins win:
Sat: Cleveland-Houston 4PM (NBC), Chiefs-Steelers 8PM (Peacock)
Sun: Buffalo-Miami 1PM (CBS), Lions-Packers 4PM (FOX), Rams-Cowboys 8PM (NBC)
MNF: Bucs-Eagles