I live in Michigan in a house on slab on grade which can be cold in winter. I have one standard size window that I am thinking to taking out and putting a patio sliding door. The house is brick which means I have to cut the brick. What I am afraid of is the winter cold. Will the room be realy cold in winter since now it will have double the glazing? even tough the existing window I have is Aluminum.Any advice is appreciated very much. Jake.