The tones in snow on overcast days are very subtle, and it’s easy to blow them out in which texture and detail disappear. The demarcation line, so to speak, between a blown highlight (an area that’s solid white) and the retention of tonality is noise. If there is even a small amount of noise, then the highlights have not been overexposed. With winter weather like you see here --a blanket of snow, low clouds and mist -- I take the exposure as dictated by the meter -- meaning, the pictures are going to be dark by about one to one and a third f/stops. This protects the subtle highlights from becoming so light that texture and detail are lost. I then make the adjustments to correct the exposure in post-processing. Alternatively, you can use a handheld light meter on incident mode to derive the perfect exposure. Then, you'd switch to manual exposure mode and use the settings provided by the meter. That’s what I used to do when I shot medium format transparencies years ago. My settings were 1/1000, f/11, and 400 ISO, and I used a 24-105mm lens.