There's a reason video game movies don't work. In a video game, you get anywhere from 10-50+ hours to flesh out the story and let the audience connect with the character. Part of the reason Arthur and John are so beloved is because we spent SO much time with them, living and breathing in their stories. By the time those games ended, they both felt like a friend, not a character.
You can say the same thing about Nathan Drake, or Ezio Auditore, or Lara Croft, or Captain Price. Whoever. We get to see these characters at the best and worst, experience their highs and lows, laugh with them and cry with them. Price's reaction to Soap's death was the first time I ever cried for a video game, and that's because we spent so many hours with them both in that trilogy.
Now, you take all of that and try to condense it down to 2, maybe 2.5 hours. It's tough, because you need to establish the character in that time too. You don't get the extended time you do in the games. That's why all these video game movies fail, because they just don't get the time to do what video games get to do.
Count me in the crowd that never wants to see a Red Dead movie. Just like I thought the Assassin's Creed movie was a bad idea because they had to spent too much time introducing the non-gaming audience to the concepts that the fans of the series already knew, I think a Red Dead movie would feel rushed after the game was a slow play. I really think it won't work, although I'm sure someone is eventually going to try.