It is available on GOG with downloadable installer and that version works fine on an offline Windows 10 system. I think I've heard that the Linux support is f

It is available on GOG with downloadable installer and that version works fine on an offline Windows 10 system. I think I've heard that the Linux support is fairly good too but I haven't used it personally. Unfortunately, it seems like essentially all games these days have at least basic phone home telemetry, even the DRM free stuff that still works if it can't connect. The only way to avoid is to block the game from accessing the network one way or anther. That being said, not everything has RedShell level stuff, although a bunch of games did and possibly others are using similar stuff that hasn't been identified. Take Two, like most companies caught with RedShell, solemnly promised to wait a while before reintroducing something like that and to do it less obviously next time. IMO, it is best to assume that games are hostile from a security perspective. On Linux, at the very least run them under a different user without access to any important data. For Windows I'm not sure that will help much due to the permissions they require but I don't know Windows very well.