Physically I didn’t really prepare at all which was a big regret once we were up in those mountains! […] I know for a fact the Battle of Winterfell night shoot was far more brutal to film for the crew and cast. But considering I only had three night shoots for the Battle of Winterfell, I would say that on a personal level the mountain scenes in Survive were more brutal [for me].
https://winteriscoming.net/2020/04/08/sophie-turner-new-quibi-show-survive-versus-game-thrones/