Will any bars or restaurants be showing the NFL game from London Sunday morning?
Maybe try the British Open Pub, they open at 9AM on Sundays and I know they show Premier League soccer games and other sporting events from the UK. Most other bars that do Sunday Brunch (one hot mama's, smokehouse, poseidon. . . ) don't open til 10AM or later. They'll probably have it on but it will be half over by the time those places open.
I was in Poseidon tonight and they were showing ads for it. Likely it will be on and they do Sunday Brunch, but they do open at 10