When thinking about contrast, think of "quality of light". Is the lighting condition more direct or is the sun light obscured and defused with cloud? Also, look at the shadows your subject presents. Is it crisply defined and definite or are edges defused and not so definite?

If you have both on your roll film, there isn't much you can do about this. I would just develop it normally and do what I can at printing time. Or, if you have extreme conditions, then you could choose to sacrifice some in favor of the other.

As to snow condition, that's really hard to guess unless I can see your negative (or the scene). Tree may be dark but it could also be illuminated by reflection snow from every direction.