I will admit that the reason I do less winter camping than I would like is because I will not do it solo.

However, I am thinking about doing my April trip solo (which is still winter here.) I took a look at the risks, and while still higher than summer - they are low. (No bears, no avalanche possible, no moving water on the route in question, should be no -20F temperatures.) I would not do this same trip solo in Dec., Jan., or Feb. I won't do the trip or postpone based on weather predictions (knowing they only get it right about 50% of the time )

So I think it comes down to risk assessment, even for summer trips... Heck solo or group trips too!