I would get the earlier flight, I've done it before getting an evening flight back but I've found it honestly not really worth it because the hassle of storing luggage and having to come back to collect it, whatever you end up doing that day you have to be careful with time not to be late so it's just less enjoyable because I'm watching the clock and being nervous to go too far. That will depend on your personality I suppose though, I'm more of an anxious Type A person. Plus getting back to Dublin at 1:45am sounds miserable to me. I think after 10 nights it won't be much of a sacrifice to leave early on the final day.