Had Dora and Friends: Into the City! not been cancelled, here's what I imagine what a Nutcracker themed Christmas episode would've looked like.

Here are three ideas of what such a special would have looked like.

1. Dora, Kate, Emma, Alana, Naiya, and Pablo helping the Nutcracker return to his kingdom so that he can save Clara from marrying the Mouse King.
2. Pablo being turned into a nutcracker after eating a cursed nut, resulting in Dora and her friends taking him a magical kingdom in hopes of restoring him to normal.
3. Characters from the original series, Go, Diego, Go! and Into the City perform The Nutcracker on the same stage from the episode "The Ballerina and the Troll Prince."

I imagine the first two special ideas involving an all-star cast voicing the guest characters. Uncle Drosselmeyer would be voiced by George Lopez. The Mouse King would be voiced by Patrick Stuart and would have two bumbling henchmen voiced by T.J. Miller and Josh Gad. The Sugar Plum Fairy would be voiced by Sofía Vergara.

Anyone who wants to make a fanfic out of this, be my guest.