Personally I would recommend Dublin and London, just did that trip myself and it was amazing. Im trying really hard to think what kind of streets Dublin had (since you said no cobblestone), but I really cant remember (I wasnt spending a lot of time looking at my feet!).

Question, since Ive never had one of these packages, do you need to stay by the expiration date, or just book? If you have to stay by it and cant get it extended, that cuts out a lot of places due to weather imo. Dublin would be quite cold.