[RGamma]

Steam DRM might not easily allow this, although I trust in Valve's ethics to permit offline play if shit hits the fan.

In fact I remember reading from a community representative that there are plans for this in place (not the best source but whatever https://www.reddit.com/r/Games/comments/18mzcn/i_asked_steam...)

[Karunamon]

It also helps that Steamworks DRM is trivially bypassed. All it takes are a couple of replacement DLL files in the games directory and it runs normally (minus multiplayer support, of course).

This isn't even a sketchy crack thing, it's an open source tool. Look up Goldberg emulator.