...although there is the poll, I'd like to add in that the Northern Hemisphere gets favouritism waaay too often on PC. Aka, DCC was originally called Autumn DCC, and well, there are other instances but I can't think of them right now
Changing to winter would just make the southern hemisphere feel more left out. :x If people don't celebrate Christmas, they don't, and, they don't have to participate. As long as we're not spreading the message of "Convert to Christianity because we said so!", then I don't see an issue.
Plus, changing to winter would mean the photography contest can't do christmas as a theme, which means, we can only do snow. And! Guess what? Australia, in most parts doesn't get snow, so Australians won't be able to participate in the photography contest. I just see changing it to Winter would be more of an issue. :x