A great idea for a blog. When I use to live in cold town the winter always really used to get to me. The main thing I would do was plan a lot of skiing trips, but as you say: expensive!!
Outside stuff was they only thing what really helped me to be fresh. Hiking and walking. Hiking gives a whole dimension to your surrouning because they look different in winters than in summer. Feel the air!!
What we would do also was go to pub-hunting. Not to get drunk drunk drunk, but we would try the special winter editon beers and then walk to a next pub. Just three of those babies are enough for you. Talk with you friends about life.
Visit a brewery! Go by bike so you can give the beers a try. Exercise and social event and maybe even learning something!