I love how cozy and chill this scene is. It's a nice little break from the craziness of the series.
I can imagine a similar scene with Quest Sprout and Momma Sprout:
It's a quiet evening in the Questwood. Momma Sprout is watching the sun set while hugging Quest Sprout as he sleeps. Going deep into her thoughts, she begins to feel anxious. As she starts to worry, she looks down at Quest Sprout, wrapped in his blanket and peacefully asleep in her arms. She listens to him breathe as his body inflates and deflates at a steady pace. Soon, her breathing matched his, and she began to feel at ease. All of her troubles have now faded away. She closes her eyes, gives Quest Sprout a kiss on his forehead, and gently whispers to him "I love you." as she falls asleep with him.
Add some gentle music and nature sounds and it'd be even better!
The quest was technically complete, since they did hunt the dragon, even if they released him after. By that account, I'd say it was a success!
This scene also really shows just how pure Quest Sprout is; He cares more about the wellness of the dragon than the reward for the quest. That's a friendship you just can't break! :)