Would it be twice or thrice effective if I used 2 or 3 or more layers of UA? I know I will have to get progressively bigger sizes because it is so tight, but do you think it would work to use more than 1 layer?

I don't think that would really work. Maybe it would but the reason under armour works is because it wicks away sweat from your body. Unless you are pouring sweat out of your body I don't think you would really need more than one suit. Maybe I am wrong though.

It won't do you as good...just get some good UA cold gear. That's what you want.