The first great feature of Dead Of Winter is that it is NOT a remake of the 1987 movie of the same name (hated that movie).
This is a German production, filmed in Finland, set in Minnesota. My experience with German movies is they are gritty, story-driven, low budget, and have zero stupid characters. Dead Of Winter has all of those characteristics.
The cast is tiny. 9 people total, only 4 of which are major players. Most of the rest of the cast is seen through Emma's memories, eventually explaining why she has made this trip to an isolated lake. As memories work, Emma never names her own character, so we don't learn her name until the final minute of the film. Even that is an add-on, as most references to her in the credits call her character the fisherwoman.
As you can tell from the preview or blurb, Emma happens across a kidnapping and tries to help the young woman. Everything cascades from there. Emma mostly has no one to talk to so the story has to convey her plan just from her actions. And in places it looks like she's making mistakes. But ultimately we learn it all comes together and makes sense.
The mix of Minnesota-nice character with ruthless moves to effect rescues and escapes is incredibly endearing and Emma plays it perfectly.
You probably won't see an ad for this movie, given the budget. But it's one worth seeing.