I've had the same problem over the years - a bag that actually fits what I want to put in it. My sweet little bride solved the problem many times by making me custom-fit bags for a variety of things - including bags for rain gear, tent poles, car blankets, sleeping pads, etc. She uses heavy duty waterproof fabrics (including camo), heavy duty zippers, and nylon webbing straps/handles.
Perhaps, if you sew

you could make a better one than you can buy. Or ...... if you don't sew ..... you could barter. Ask your spouse to do it in trade for something she wants ...

... like a weekend at the beach, a nice dinner out, or a coyote hunting trip!