Let me first just say that I haven't been to Ireland, but I have been to Europe in all kinds of weather. It's all about layers, and I'm a fan of LLBean as well. I went to Europe for a month in January and did not bring a winter coat. Our weather ranged from warmish, sunny days in Barcelona to snow and chilly weather in Austria and Switzerland and somewhat chilly weather with a small dose of rain in Paris. I brought a very light weight and warm long underwear (top looks like any other LS top), a lightweight wool sweater, a LLBean pullover fleece, a very packable LLBean lightweight puffy jacket meant for about 30-40 degrees, and a rain coat. I usually just wore a few of the options, in Switzerland, I wore them all. A raincoat on top of anything stops the wind and adds a lot of warmth. If you are not sure about a hat, why not try one of the thinner, smaller hats that won't take up much room or just make sure you have a hood. I have a cozy infinity scarf that I pull up over as a hood on occasion, and then my husband laughs at me. ;) I always bring the cheap, thin lightweight gloves because even if its 40s/50s, when its damp or dark it feels good to have some gloves.