Your take on the possibilities is a bit more optimistic than mine was. I automatically assumed she was done for (perhaps just viewing the 1982 film the night before had something to do with that, as those characters have no vehicle to escape in). Did they say the Russian base was 50 miles from the Norwegian base? Did they mention how far the spaceship was and where it was in relation to the Russian base? I know they showed at least one map/image but the information did not stick in my brain.
Not mentioning the American base is slightly irritating. I mean it can't be too far. Or maybe it was very far away from the Norwegian base and the guy in the helicopter is just a really, really bad shot. And has a ton of ammo.
In dialogue they say that the Russian base is 50 miles from their location just as they're climbing into the snowcat at the end and that the cat has enough fuel to make it. This is just before MEW toasts him.
In the original the Norwegian base is an hour away from the American one by helicopter, depending on terrain and other factors it's possible
the American base cannot be reached or is too far away to be considered before the American one is. It would've been nice if we were told this or the American base was given some
mention, but for whatever reason we weren't.