Hi Orvar, you asked for a critique, so here it is! Completely subjective of course, but you knew that. It's also going to be quite short since I don't know what I can say that you don't already know so I'm going to stick with what I got out of looking at it.
The composition of the shot bothers me a little. Obviously you have no control over the shape of the aurora, but that does work well with the angle of entry into the shot and the lovely curves. The clouds give it some good structure - layers of interest if you like, but the house / shack doesn't seem quite right. Why?
Firstly it is in the middle, so it grabs my attention, but it isn't very interesting. It is competing with the aurora for my interest, and loses but won't go away. It also looks a little over sharpened. Finally, the house (and clouds) are very red - possibly light pollution combined with a long exposure and the resulting white balance issues? I don't know if you could have toned this down to a more natural colour but I suspect that it would look more pleasing.
Of course this is all nit picking in what is a very good capture of a beautiful scene, so congratulations on that!
I am always so jealous of Northern Light photos, it is a sight I want to see some day. I love the processing on this shot, the tones of the building work beautifully with the lights. Nicely done, good luck in the challenge.
For someone who hasn't seen an aurora live, I can only envy all you Icelanders. Very well captured with an interesting foreground. The faraway houses and the tiny glowing chimney are slightly distracting, but I see them only after I spend a fair amount of time on the scene. Looks like it was windy too - with all the grass motion in the foreground. Worth your effort I must say.