What you could also try is just stay at the 3 Ducks for a night or 2 and get all your sightseeing out of the way. Then hunt around for a hostel with no lock out time.
Cause lets face it, when you've partying till 6am the last thing you want to do is drag your ass out of bed and walk around in the hot sun!
I've been a wild rover for many's the year,
And I've spent all me money on whiskey and beer.
But now I'm returning with gold in great store,
And I never will play the wild rover no more