Losing internet. Is there a way to play offline and have DLC work for SP?

Basically what the subject says. I am going to lose internet in a little while....probably the end of this month or the beginning of next. I would like to be able to play my bought and paid for SP game and the SP DLC. Is there a way to do that yet? I can play the SP base game now, but without being connected to the internet, the DLC won't verify and I can't even use my saves. Why the hell do we have to verify the DLC every time? STEAM lets me play Skyrim and its DLC offline so I know it can be done. That wouldn't stop the people getting the game illegally anyway. They always find ways around DRM.

This is for PC btw.