There's still sun during the winter; you just need more solar panels for the same amount of energy. Also, there tends to be more wind during the winter, so wind power makes a good complement to solar.
So the winter, by definition, will always generate less? or we're just like... covering up a bunch for half the year or something? I don't get your point.
My larger point is that solar is only ever going to be a piece of the puzzle at best. In space it might be quite nice, but otherwise it's kinda goofy to invest too much in.
In lower latitudes, yes. Where I live December has an average of 4 hours of sunlight (yes, the entire month).