I actually don't find it odd that you like the winter over summer. Summer used to be my least favorite season until I learned how to swim at the age of 34 and got a swimming pool. Now I don't hate the summer like I used to. But I still love cooler weather myself. My favorite drink is hot tea, and I love to "hibernate" with a cup of tea. I also like to bake and do crafts, which are both more enjoyable in the colder months.
As far as the IBS in the summer months, mine seems to flare up even before I change my eating habits. It seems to somehow be associated with the change in seasons, or maybe the heat. I just seem to notice a pattern there and wondered if anyone else experienced this.