HBO recently aired a "Coming in 2017" promo during last night's episode of Westworld that showed a few glimpses from Game of Thrones Season 7.
In the promotional video, we see Sansa Stark, Jon Snow, and Arya Stark riding on a horseback. Snow appears to be in Winterfell, but it's rumored that he will head South to meet with Daenerys. It's most likely he will be involved in the war against the Lannisters at the epic battle in what appears to be Highgarden.
The promo hasn't been released online yet, but expect it to surface soon. Game of Thrones Season 7 is currently filming and will premiere on HBO on Summer 2017.