Dublin or Rio? Nobody in either of those places gives a hoot about American football.
How hot would Rio be in early February? That’s summer there.
The Munich, Germany game seemed to be finned with people who actually care.
https://www.youtube.com/watch?v=7QX5bLsmJrU
There’s only two locations that would fit....UK (London) and Germany (Berlin/Frankfurt/Munich). They can fill a stadium completely. Time-zone-wise, it works as well....evening game in Europe...showing at 2 PM in the US. I’d also guarantee that more than half the seats would be occupied by Americans who either live in Europe or will fly over for the event.