Ahhh, read your photog comments ... snow is good, very good, IMO. I know often they want to deport me for comments like that. I really like your scene. And you're right snow helps, sure does.
A valid question. When I shoot in manual, I assume a hierarchy of adjustment. Shutter speed, aperture, then ISO.
I generally adjust shutter speed, rather than aperture...especially when there's lots of light.
When light is scarce, I tend to lean more on aperture adjustment to get the exposure I want. In extreme cases, I adjust ISO.
For this shot, I was standing beside my car on a busy rural road. The fierce wind was causing frequent white-outs. The wind-chill was near -30 Celsius. My camera does not like the cold, and I knew I had maybe five or six exposures before it froze up, so I snapped as fast as I could and kept the best of the lot.
Since then I've come up with a system to keep the camera warm in the bag. I use several gel packs, warmed up in boiling water and packed in the bag around the camera. It works quite well.
I love the feeling behind this photograph, of the sun rising out of such darkness. The simplicity is also lovely, the message got across to me without a whole lot going on in the photo. Good job.