[UPDATE] – Ubisoft has confirmed the Open Beta will start on the 18th February for Xbox One users, 19th February for PS4 and PC and conclude on the 21st February.
Quite a few sources have come across a rumour that The Division is going to have an Open Beta between the 16-21 February. If this happens to be true everyone can get a chance to see what this promising game will be like. I highly recommend you give it a go.
The Closed Beta size weighed in at 26gb so I would expect if the Open Beta does occur that will probably be the size.