It's the trainer for me, with trainer road. (Haven't tried swift yet, but I have a "dumb" trainer.) And when the temp in in the upper 20s and above, I ride--20 miles in that kind of cold is like 50 in the summer.

I'm dying to get a Fat bike, but finances won't allow it. (Been working on the girlfriend to get fat bikes for her and the kids--which would give me an excuse, you see what I mean?)