The development of “Frozen” took many, many years, beginning long before computer animation existed. Though it has clearly been a massive success in its CG release, there was a time when Disney considered following in the footsteps of its many timeless film classics to create the story of Anna and Elsa using traditional 2D hand-drawn animation.
Even during the planning process of the CG film, 2D artwork was used to develop the look of characters and environments.
Disney virtual development artist Cory Loftis has posted some of that 2D art from the early days of “Frozen” with gorgeous results, mostly from the “Love is an Open Door” sequence but also featuring Marshmallow, the snow monster, and the wolf chase. If “Frozen” did end up being a 2D film, this is what it could have looked like.
Many of these images (and more) can be found in the book The Art of Frozen.