Are there any anime series that are predominantly set amidst the season of winter and preferably in nature? - I really haven't been able to find anything and was just curious, especially since I love wintertime imagery (and naturally it's my favorite season as well, haha). Thanks in advance!

Kanon is a great series and its set in winter the whole series.
Its not entirely all in the nature, but a good deal of it is.
Check it out.