Opening up two stops from a snow (Zone V) indication on a meter is a sure recipe to gain gray snow. I would filter the lens with a yellow filter (internal reflections within snow are normally blue in color). The yellow filter will tend to darken those reflections and gain separation of the white snow and the internal reflections. This will help to indicate texture. I would open up three stops (Zone VIII value rather then Zone VII). If your film is properly rated and your development times are correct this will give you a nice tonal separation within the snow.