Let me say that I'm a long-reformed former overpacker. The above sentence just JUMPS out at me as symptomatic of the problem and how it can be fixed.
First off, repeat after me, NO JEANS!!! (Well, you can have one pr. *if* you are going horseback riding, but no more!) Jeans are heavy, bulky, take forever to dry, and do not keep you warm when it is cold. They are a terrible choice for any kind of travel. Instead, pack zip-off pants or lighter trousers such as windpants or khakis, plus two prs. of very thin long underwear (I like silk, but hi-tech wicking fabric is good, too. And yes, you can buy it for kids.)
One water-resistant fleece jacket and pr. of gloves packed in a space bag will keep you warm when worn over a t-shirt; no need for as many long-sleeve shirts as short, and wearing the tee underneath keeps the fleece from getting smelly. Fleece also resists spills, so that's a plus, too.