Early this morning, Guerrilla Games announced via Twitter that Horizon: Zero Dawn DLC, The Frozen Wilds, will be available November 7, 2017.
The Frozen Wilds was announced at E3 during Sony's showcase, with a bit of theatricality, and will have players exploring a new area in Horizon's open world, as well as a new tribe that didn't get too much screentime in the main campaign.
The Frozen Wilds will be $19.99 USD at launch, but PS Plus members can pick it up a a bit of a discount for $14.99. Pre-ordering also gains players a special Banuk Aloy avatar.