Considering most stuff is in the online only, what will happen once GTA5 servers shut down? Is there a way to play local GTA5 servers?

Every game eventually shut down their server, and most likely GTA5 once GTA6 online is active, it will be decommissioned. At that point most content will be gone, as it lives on the server and can't play it on the "story" version of the game.

Is there anyone that made a offline server/local server for GTA5, to play even if the server is offline basically? You can play games like Diablo 3 totally offline these days, running a local server; and same apply for The Crew 2; so I thought it would be just a matter of time before someone makes a GTA5 server for local usage?