Imagine if they threw in some conflict to the Ramsay win parade.
Let's start at the beginning. Ramsay's introduction was perfect. Horn blower, Theon thinks he's being saved, really good stuff that should be in there.
Then throw in someone who doesn't agree that Theon should be mutilated. This would fit into how Roose told Ramsay he "wanted Theon whole". Ramsay debates this man and ultimately kills him in a brutal fight in which Ramsay receives as many licks as he gets.
Theon makes a desperate attempt to fight Ramsay before he is made to be Reek. He nearly kills him before Ramsay's men show up and chain Theon back up.
Then in season 4, actually flesh out Roose and Ramsay's twisted relationship. He not only distrusts him, but he wants him hanged for what he's done at the Dreadfort. Instead of sending Locke on that utterly pointless excursion, Ramsay travels himself but ultimately fails to find Bran and Rickon. This creates a desperate Ramsay, one that will do anything, which prompt the whole Moat Caitlin trick. See, Ramsay is just as sick and twisted, but he's also experienced some setbacks.
Completely cut the dog thing. Have Theon chained up. Yara tries to rescue Theon in dead of night but Reek stabs her in the heart.
So after Moat Caitlin is captured, Roose makes Ramsay his heir and everyone returns to Winterfell. They could even leave in Sansa marrying Ramsay, only change the circumstances. Sansa is taking Robin Arryn on a tour of the countryside when a group of Bolton men kill all the guards and take Sansa hostage, bringing her back to Winterfell. Roose warns Ramsay not to lay a hand on Sansa because she's too valuable as a prisoner. He warns him not to cross him again. This creates tension. What if Roose found out? It's not just Sansa in danger.
Roose reveals that fat Walda is pregnant and tells Ramsay that he shouldn't take anything for granted.
Then of course introduce some northerners. Perhaps a northern plot JUST to kill Ramsay. They know what he's done. Their plan fails however when the plot is discovered.
Ramsay kills Walda and her unborn son to Roose's indignation.
Littlefinger meanwhile learns of everything and tells Cersei, which now actually makes sense because he'd need her help. Ramsay meanwhile meets Sansa as his true self, and she knows what is in store for her. None of this "playing the game" business.
So after winning his father's approval and title, he must keep it by winning battles against the Baratheon forces. He manages to disrupt their supply lines through several daring (but plausible) excursions with a few hundred (not 20) men.
Then at the end of Ramsay's storyline, Roose puts him in the vanguard, sure that his vicious son will be the first to die.
Ramsay emerges from the battle however, having sneaked around the advancing Baratheon forces.
The Boltons receive reinforcements from the men who defected after Shireen's sacrifice, and manage to rout Stannis' army.
Stannis is bloodied. He can barely walk. Same scene as in the show. He hears men dying. It's Ramsay. Ramsay tries to kill Stannis but it stabbed through the neck in the same way that no name Bolton soldier was in the finale. So that's the end of Ramsay and his storyline, his arrogance, and his invincibility.
Brienne meanwhile does help Theon and Sansa escape on horseback along with Pod. They each take one in tow.
The Boltons still win, and Satan was still used to his full potential.
