The NFL’s international games do require one team to give up a “home” game so that they can serve as the “host” for the game in question. This is why it is so impossible to believe that the Cowboys would ever “host” one of these as home games are so valuable for them.
But it is obviously possible that Dallas can be the visiting team for a game like this as they were for their last international game. The Cowboys “visited” the Jacksonville Jaguars at Wembley Stadium in London. As noted, they will visit the Jets in 2025 and that visit could, in fact, happen at Tottenham, especially since it has now been over a decade since the Cowboys have played an international game.