User blog comment:JackFrost23/Effects of GameSpy Shutdown on Red Dead Redemption/@comment-87.0.65.64-20140514092916/@comment-205.144.217.130-20140527085101

I would say yes. I just finihsed obtaining the last of them, and have verified that you can use them without a network connection. Make sure you have a save with them all if you want a truly "Complete" file for effing around with.