Will my quilt jacket be too stiff to break in?

Hi, I just need a little help from people a little more experienced with different fabrics than me! My boyfriend's birthday is coming up, and for his present I want to make him a quilt jacket, because he hates synthetic/plastic fabrics and he's told me he would love a quilt jacket one day. Because he goes to school in a very cold area, I want to make him something that's made of natural fibers and warm. From my research, I think that it would be warm enough if I were to make the quilt top with duck cloth, use wool batting, and wool flannel for the lining. I think it should be sufficiently warm, but I'm worried on whether it would stay extremely heavy and stiff. He's already expressed that if I were to make him a jacket he would probably end up beating it up because he'd wear it daily and work in it, but I'm wondering if it would be too difficult to break in if its extremely thick and difficult to move in. Would it be impractical to use these materials, and if so are there any natural alternatives I could use?