I loved Descendants as a movie and I think it would be a hundred times better as a new Disney TV show. Have it surround around the four kids and their family drama while also trying to find love and occasionally tempted to go back to evil.
Mal could be ready to become queen and visit the island of the Lost for a farewell, but to meet Francis the evil son of doctor Facilier from the Princess and the frog and he shows her how good being evil can feel that she has to choose between Francis and Ben after their affair is revealed.
Carlos should really be shown more. He seemed more like a sidekick in the first movie, but I was thinking he meets Irina the daughter of Elsa. At first Irina tries to stay away from him because she can't control her powers, but Carlos constantly fights her and when he's about to die with an act of true love she saves him and learns how to control her powers.
Evie meets Tara the wicked witch of the west's daughter and become friends. Tara teaches Evie how to be a witch and how to use the magic she hasn't tapped into, but the magic Tara teaches Evie is wicked and evil. Doug sees the changes in Evie and tries to bring her back to her old self, but once Tara puts on a curse on her to cause her mother, the wicked witch of the west to take over Evie's body Evie is gone. Her friends are able to find some way to get her back before the wicked witch can take total control of her body and she finally admits her feelings for Doug.
Jay starts off not liking his life in Auradon because he feels bored of the same old things, but meets Penelope, Peter Pan's daughter and she takes him to Neverland to be a part of the Lost boys. At first Peter Pan isn't very fond of Jay, considering his relationship with his daughter but slowly accepts the thought of having him on the island. Pan tells Jay about his time with the wicked witch and Jay is quickly able to put together the pieces that Evie is in trouble, so he raced back to Auradon to save Evie and realizes how much he missed his friends. Jay is able to convince Penelope to stay in Auradon with him and they become a couple.
I know this seems like a lot, but everything I wrote could be the first season of the TV show I have in mind and the rest can come easily with time, considering there are so many Disney characters and their children that the first movie didn't cover.