Have you tried Goldfrapp?
I am also a HUGE fan of Madonna's Frozen. One of my favorite songs from my childhood. I even shot a homemade music video to it. Because I didn't like hers so much.
I'm also a fan of Enya. Not sleep at all. She's very gifted.
This is making me thing of another interesting track you might like.
This is by a Belgian band called Hooverphonic. They have an impressive discography so have at it. Good luck btw. I have a handful of other suggestions if these are not your style.