You don't really get winter sun anywhere in Europe, if you want guaranteed winter sun you need to go further, I've done Christmas in the Caribbean, India and Mexico, the Caribbean was best but it's pricey and some of the islands (particularly Jamaica) are in a mess at the moment.
i get what you mean, but compared to the uk, greece in winter is paradise with the weather, i prefer it
summer is way too hot
but just having more sunshine than the constant gray skies of the uk is a treat