Wrap yourself in history at The Hotel Viking, a member of Historic Hotels of America, nestled in the Historic Hill district on famed Bellevue Avenue, which opened in 1926 to accommodate the haute monde (https://www.historichotels.org/us/hotels-resorts/the-hotel-viking/). Another great choices...
in about 2-3 weeks. Ireland is full of wonderful choices but it seems the west coast might be the highlight of those days of your trip. I might suggest skipping Belfast entirely, flying into Galway and proceeding as planned with an extra day in your pocket for that part of the country...