I'm too new a quilter to have encountered this yet, but there's some product on the market that you can spray on a fabric and it gets the wrinkles out. I'm thinking you could hang your fabric from your shower curtain rod and spray it with this, maybe? It's marketed for clothes, not quilting/sewing, if that helps you find it.
Then again, my beginner class taught that we pre-wash fabric to get the finishes off before using it, so this just puts on another type of finish. Still, you may want to consider it.