Pinkie Pie Says Goodnight: Backup Plan
I'd enjoy seeing a little bit more of Cadance's reckless/flippant side. Some may think I dislike her, which is not true. I would like to see her challenged more and meet those challenges without deferring to others. If she can be more forward, as she was with Twilight on Once Upon a Zeppelin, I will gladly celebrate her character more.
The background comes courtesy of Hawk9mm, but his DeviantArt account seems to have vanished. Not sure what happened. 's page is still going. You should check out his history of Pinkie Pie Says Goodnight comics!
I like to imagine the Crystal empire being somewhat more militarized since it sits on the border of both Yakyakistan and the Griphon kingdom which both have had shaky relations with Equestria.
It also is a strong fortress with it being a bastion of life and warmth in an inhospitable tundra. Starving them out isn't really feasible since your own army would starve first.