This achievement occurs between the plot points of Act 2 Chapter 3 and Act 2 Chapter 4 where you're playing as Kait and Del. You'll essentially be traversing a lot of snowy land on a glorified snow-plow doing fetch quests for roughly an hour. (A rather slow portion of the campaign.)
As presented by YouTubers "Monkey Magic" & "Video Games Source" here is some gameplay to help you monitor where exactly your pacing is toward getting past the wall.