Here's a possibility:
NFC East - NYC - London, NYC - Toronto, Washington - London, etc., great potential for even more new great rivalries
Dallas Cowboys
(London)
New York Giants
Philadelphia Eagles
(Toronto)
Washington Redskins
NFC Central
Chicago Bears
Detroit Lions
Green Bay Packers
Minnesota Vikings
St. Louis Rams
and one team moved over from the AFC East
NFC West - Largely a reunion of old NFC West foes from back in the day
Arizona Cardinals
Atlanta Falcons
Carolina Panthers
New Orleans Saints
San Francisco 49ers
Tampa Bay Buccaneers
AFC East - unfortunately this is 7 teams, so one will have to switch to the NFC Central
Baltimore Ravens
Buffalo Bills
Cincinnati Bengals
Cleveland Browns
New England Patriots
New York Jets
Pittsburgh Steelers
AFC Central
Miami Dolphins
Houston Texans
Indianapolis Colts
Jacksonville Jaguars
(San Antonio) [or Oklahoma City]
Tennessee Titans
AFC West
Denver Broncos
Kansas City Chiefs
(Los Angeles)
Oakland Raiders
San Diego Chargers
Seattle Seahawks - back to the AFC!
This is of course only one of many possibilities.
The idea of a London team is ridiculous enough without putting it in the same division as flipping
Dallas. It would have to go in the AFC East, where all the teams really are near the coast.
But, just for the sake of argument, if we were to go to 36 teams this is how I'd do it (and if we go to 36 that's enough for Jacksonville to be justifiable). Note the lack of team in London:
NFC East: NY Giants, Washington, Philly Eagles, Dallas Cowboys, Carolina Panthers, Tampa Bay Bucs
NFC Central: Chicago Bears, GB Packers, Minnesota Vikings, Detroit Lions, Atlanta Falcons, NO Saints
NFC West: St. Louis Rams, San Fran 49ers, Arizona Cardinals, Seattle Seahawks,
(Los Angeles),
(Portland)AFC East: NE Patriots, NY Jets, Buffalo/Toronto Bills, Miami Dolphins, Jacksonville Jaguars,
(Tidewater)AFC Central: Baltimore Ravens, Cleveland Browns, Cincy Bengals, Pittsburgh Steelers, Tennessee Titans, Indianapolis Colts
AFC West: KC Chiefs, Denver Broncos, San Diego Chargers, Oakland/LA Raiders,
(San Antonio), Houston Texans
Or, if the Jags move, slide the Colts to the East, the Texans to the Central, and that opens up OKC or Mexico City as possibilities.
As for the "Tidewater" choice- the Hampton Roads area is the largest metro in the nation with no pro team. I guess that's kind of R**s***s area right now, but whatever. San Antonio is kind of Cowboys country, too, and so is OKC.