Frozen with a Twist: Anna and the Evil Queens

Like the title says, it's Frozen, with a twist. (A huge twist)

Elsa's coronation is right around the corner, and every princess is invited. Well, almost every princess. Everyone knows Maleficent and the Evil Queen, two of the most feared royalty in all the land. But they aren't the ones who are mad, that would be their daughters, Princess Splenisterid and Princess Prinhildy.

Though Splenisterid doesn't really care for invitations, she is all about revenge, so when Prin informed her of the loss of invitation, as well as a plan to get back at the royals of Arendelle, Splenisterid readily agreed.

Together, the uninvited princess cast a spell that releases Queen Elsa's ice powers from her control, causing her to run off, and for the towns people to hate/fear their Queen. Then with a second spell, they release Elsa from her boundaries and cause her to be "evil" like them.

Now the question is, can our favorite heroine rescue her sister from the evil princesses (and maybe the princesses themselves), while avoiding the attempts to freeze her heart, and still get the guy of her dreams?