These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
We never see the much hyped "Liam Neeson vs. a wolf" showdown at the end of the film, and only get a glimpse of its aftermath after the credits. However, it's possible that the filmmakers intentionally didn't show it, because nothing they could film could possibly live up to the hype. Thus, the viewer is left to imagine how awesome it was, and come up with their own versions of it.
It's the middle of winter and there's no fire or other means to stay warm. Hypothermia would have set in within minutes after Ottway crawled out of the river... and it quite possibly did. Ottway took off his heavy jacket after getting out of the river, and in later scenes he's not wearing his hat or gloves either. One of the symptoms of severe hypothermia is a false sense of warmth, in which many sufferers take off various layers of clothing (called paradoxical undressing). This is responsible for a large amount of hypothermia-related deaths. Since we don't really get a good shot of Ottway after his fight with the Alpha, it's very possible that he won but died of hypothermia soon after.
The wolf calls in general but especially the Alpha's.
Holy Shit Quotient: Just how much worse will things get for Ottway and his companions? The ante gets upped every. Single. Time.
Visual Effects of Awesome / Scenery Porn: They filmed in a real wilderness in Canada and it looks beautiful. The wolves are also not CGI, but (mostlynote they were digitally enhanced in many shots) animatronics and puppetry, and they still look really good...and TERRIFYING.
Hell, the film features Sound Effects Of Awesome as well. In the theaters you will feel the power and intensity of the plane crash and your bodies will quake from the sounds of the wolves. . .