If we are to believe the said information, the game is set in Honolulu (capital of the U.S. state of Hawaii) and the map is bigger than GTA San Andreas. The game will reportedly offer an even greater world than Grand Theft Auto: San Andreas.
These screenshots and video may well be from any mod of the game, so it is currently at least questionable whether these really are scenes from Grand Theft Auto 5. That is, if you can actually see and infer the video at it’s current quality.
The video and screenshots have been sent by a Rockstar Employee, the uploader claims.