Yay! Another great song from johnfn! Since it seems like everyone else has covered all the big stuff, this review is probably going to be really full of nitpicks.
The bad stuff:
You know what annoys me? Constantly having to change the volume on my earphones. Basically, I think the buildup at 1:35 is a bit too loud. I guess it's hard to transition that, but I probably would've made the white noise volume lower. Speaking of transitions, I think the one at 3:09 comes a little abruptly. Perhaps you could've had some other pads or strings in there, subconsciously building the ambience up a little. I also think the little synth trills at 1:58 and 2:07 are sort of unnecessary, mainly because they don't really fit with the tempo.
I can see the piano break in the middle as being the 'empty land' part of the song, but if the first snowfall is the transition at 3:09, what's the first part supposed to be? Personally, I think the 'empty' part at 2:43-3:08 is a bit too empty. Sometimes, nothing happening can be really effective, but I don't think this piece quite pulled it off. It was done pretty well, but it just doesn't feel... complete, for some reason. Stupid inability to express my inner feelings through vocabulary. In the same vein, this is probably the ending of yours I have the biggest problem with. Normally, they're fun gimmicks, but this one just seems empty. I know that 'empty' is even in the title, but I just don't think the ending fits.
The good stuff:
The part from 2:43-3:08 was quite empty, but you did have a really cool atmosphere going on before that. The pads you used really made it sound desolated and bleak. The pads seemed really well mixed and fit in perfectly.
As usual, the sounds you used were amazing. One of the standouts was that sexy piano thing at 3:59 and 4:16. I also particularly enjoyed the plucky noises at the beginning, simply because they remind me of the intro of a Waterflame song I really enjoy, Slipping Into Madness (which has a COMPLETELY different mood from this one, but pluckity pluck nonetheless).
Basically, this was another great piece. All the compliments people have given you already for this song are echoed by me, and it seems you just keep getting better. I know this review seemed a bit negative, but I've just gotten back from a long trip and I'm tired and rambling and there's probably going to be tons of grammatical mistakes and I should stop typing now.