Double check the workwear stores too. In canada was have something called "Work Wearhouse" and there are similar things in the states - the kind of stores that sell to people working on construction crews. A lot of the stuff is tough as nails and heavy (like Carhartt Cotton duck overalls and the like) and not the kind of stuff I'd take backpacking, but most of them also carry waterproof breathable jackets, fleece, and nylon stuff that is suitable - often in larger sizes.