No single camouflage will work well in both woods and snowfields. Obviously you'll want to wear all white in a snowfield on open ground, but all white in the woods is too bright and makes you stand out. In evergreen areas, with trees that have branches close to the ground, you're often better off with regular woodland camo. If the branches are higher up, white pants and a woodland camo top is the way to go. In deciduous areas (most hardwoods), one of the white/grey patterns will work best.
If I had to pick one pattern that's best overall, I'd say the German outfit that's reversible from all white to white/dark green. Brush on about twice as many green splotches on the mixed side of the jacket/parka, wear the pants white side out all the time, and reverse the jacket when you move from snowfield to forest. Yeah, it's a pain, but so is being "killed." Obviously, change to all white BEFORE leaving the treeline,[:D] and wait till you're in the woods to change to the woodland side.