Luckily for you, Don Bluth and the other animators based their designs for the film on Marc Davis' artwork for Disneyland's Enchanted Snow Palace ride (the movie, in fact, looks like Davis' concept art come to life). So, you actually can see what Elsa, at least, looks like:
Picture that, but some larger facial features to make it easier for her to emote, and you've got Elsa from The Snow Queen.
Maybe you could have the top design be what Elsa looks like in the beginning and one of the latter 3 be Elsa at the Climax.Personally always preferred some of the other concept designs they did for the Snow Queen, mainly because the crown she wears looks a bit too big and ridiculous, as are the icicles in the dress.
The third design to the right above is I remember correctly was adapted into Elsa's OTL outfit, with the exception of the see-through cape which they added after, and the hair change they gave Elsa.