Is my 8 day itinerary doable?

Hey guys, visiting the Lofoten Islands and experiencing the breathtaking landscapes has always been a dream of mine. Today, the airline had a campaign with cheap tickets, and I bought them on a whim. I have no idea what to do or how to plan things yet, but here’s what I’m thinking:

• September 9: Arrive in Oslo at 12:15 PM, check into a hotel, and spend the day exploring the city.
• September 10: Fly to Leknes and rent a car.
• September 10–13: Drive through Lofoten. I really want to do the Reinebringen hike, so I’m planning to drive from Leknes to Reine, then backtrack to visit Henningsvær.

Do you think four days is enough to cover these areas, or should I extend my stay elsewhere?

I return on September 16, but I’m unsure what to do on September 14–15. I’m considering either:

• Returning to Oslo on the 13th, flying to Bergen on the 14th, and coming back to Oslo on the 15th; or
• Traveling from Leknes to Bodø and taking the train to Oslo.