If I delete an episode, is there a separate save file that will keep my decisions? Sorry, I couldn't extract the answer from your response—it seemed to imply your decisions are saved unless you delete the entire Walking Dead Season 2 app.
Yes, your saves are stored in the base application (along with Episode 1). You should be able to delete Episodes 2-5 to create more room on your device. As long as you keep the base game application installed, your saves will be intact.
You're welcome, enjoy the game!