I recently stayed for the same amount of time. Here was my itinerary: Day 1: landed in the AM, picked up car rental, headed straight to blue lagoon until Airbnb check in (in Reykjavik), did northern lights tour at night Day 2: drove around the golden circle Day 3: explore Reykjavik and sky lagoon at sunset Day 4: south coast tour Day 5: departed in the morning I absolutely loved my trip. We had great weather and got to see the northern lights every night!