Far more energy and natural resources are going to be used to make those big screens than melting some sand for glass. Double wall glass doors with a good vacuum are incredibly effective insulators too. I doubt infrared radiation that goes through the glass is a big concern in the real world--unless your 7/11 is on Mercury.
Glass is very energy-expensive to manufacture. It softens around 1000 degrees centigrade and melts around 1500 degrees centigrade, which makes it incredibly expensive to recycle into a product with a different geometry. For glass bottles at least, "recycling" consists of washing the bottle and shipping it back to the bottler. (Here in Korea, people use the empty bottles as ash trays, and occasionally a bottle with ash still in it is delivered to a consumer, making the news.)
