I have a Thermarest Ridgerest foam sleeping pad but I want something warmer, more comfortable, and more form fitting than the foam pad. I saw people using Sunshades for windshields as insulators because of the aluminum and thin padding to hold it together. I decided to make a combination of a sleeping pad, blanket, and insulator. Someone else probably had this idea before I did I just haven't seen it. It would consist of 3 layers; A wool blanket folded over as many times to get half an inch thickness, A Sunshade or two sown together to make it as long as needed, and A thin nylon cover on top all diamond cross stitched to make it thin.

Is this a good idea? Does anyone have anything like this?