Yep! Added it last fall, helps quite a bit, my fall crops kinda fell apart, but I was able to start growing Jan 11th this year in the GH, partly cause of the bubble wrap, started seeds inside a grow ten, inside the greenhouse.
What a lot of the big growers do, might work better though. They add a 2nd layer of plastic, and then ad a small little mushroom fan. It inflates the gap in between the layers of plastic, and does basically the same thing, but with less hassle than what I did. once summer rolls around, and it becomes to much insulation, they simply turn thew fan off. Bubble wrap works really well for a small area though.