I don't know any.
The article assumes that anyone who identifies as Christian is Christian, and probably the pollsters did, too. We would say, certainly, that removing God from the creation itself IS a denial of who the Bible reveals Him to be and if we don't believe the Bible's revelation of God, we are not Christians. The Bible's revelation of God is consistent that He created the heavens and the earth and all that is, and that He did so through the person of the Son. Denying any element of that is to deny Him and to deny Christianity no matter how you self-identify.
So, in Iceland, a lot of non-Christians --- deceived as they may be and without imputing animus to them in their identification as Christians --- falsely called themselves Christians and went on to deny the person and work of Jesus Christ. By any remotely biblical understanding of who Jesus is, this is not only non-Christian, but is the actual antichrist spirit that is as old as the resurrection of Jesus.
The real story here is simply this: Iceland has apostasized and doesn't know it. Friends, that is the testimony of the western church, the American church, and if we are not cautious, us, too.
Lord, help us because we are a hot mess.