My thoughts on the matter as a recumbent owner
Well, I shall try to respond effectively, but it must be pointed out at the start that I have no experience riding a DF bike in winter (at least not in winter in places where there is snow). I ride the recumbent, Challenge Hurricane, and the recumbent, Bacchetta Corsa
Here are my observations:
In winter, slipping on the ice is a possibility, and on a recumbent, if you fall, you fall from a lower point and therefore the fall might not be as damaging.
I would say that falling snow is a bit more likely to get in one's eyes when one is on a recumbent, simply because one is more reclined
Some recumbents come with what are called disc or hydraulic brakes, and these brakes may be more effective in stopping in winter. My Challenge Hurricane features such brakes.
Presumably, a recumbent rider deals with less of a wind chill factor, simply because he/she is on a more streamlined bike
Some recumbents come with fairings which will aid in blocking off falling snow. Heck, some fairings completely enclose the recumbent (e.g., the awesome Go One recumbent tricycle).
Going up an icy or slushy hill might be a bit more problematic on a recumbent, but again, I've never ridden a DF bike under these conditions
The recumbent seat being longer and more extensive, more snow and ice are more likely to accumulate on it; but you just wipe off the snow and ice. Still though, because some of the water sort of gets absorbed by the seat, your back and buttocks might wind up a bit more wet than they would on a DF bike.
Winter is known for having less daylight, and one must remember that most bicycle lights (particular headlights) were designed with attachment to DF bikes in mind. Nonetheless, I have successfully attached a headlight to my Bacchetta Corsa recumbent, and if necessary, could probably figure out a way to attach a headlight to my Challenge Hurricane. Taillights are no problem.
Well, that's all that I can think of.