Complex sentence: After the incredibly cold winter passed, the summer came and the whole island became green, which stunned place was in fact habitable, despite the horribly cold winter, and full of useful resources, Flóki restocked his boat.
Split into simpler sentences: After the incredibly cold winter passed, the summer came and the whole island became green, which stunned Flóki. Realizing that this place was in fact habitable, despite the horribly cold winter, and full of useful resources, Flóki restocked his boat.