Dublin 11-26 to 12-1

I am sorry that I cannot answer your question as to what is open the week after Thanksgiving; but I can tell you a little bit about the extended trip I took in May 2015. If you want to get some good info, go to my "Dublin Trip Report - May, Suggestions and Feedback" which I published on TripAdvisor. I think I published it in January 2016. Use their search function to find it.

1. Basically, I highly recommend the Mary Gibbons Newgrange Tour. Google it to find her website. It is a great day trip, but not too long for a day. Mary is a walking, roving history book, so you get a whole lot more out of it than just being at the site. Mary does book up, so plan early. This is one tour which I do recommend that you do not try to do on your own. Even bring a notebook with pen because you will get a full Irish history lesson.

2. Since you do have a car, I would recommend spending a full day in Belfast. You can do the Black Taxi Political Tour in the morning and the Titanic Museum Tour in the afternoon. I really do believe you need a full day in Belfast.

3. Finally, if you have energetic kids with you, they may love climbing the Giants Causeway. It is magnificent, but it is too much for a bus tour -- too long on a bus. Make sure if you do a tour to Giants Causeway that it includes the entrance fee to the new Visitors Center. Having admittance to the Visitors Center will provide some level of comfort on a cold, windy winter's day.

If I recall correctly, Belfast and Giants Causeway are on the pound sterling and not the euro -- so consider being prepared for this.

Have fun. You will love Dublin and the Irish people

For Dublin, I believe that most everything will be open that time of year. It is usually some of the smaller towns that will close some attractions after the tourist season. Some of the Dublin attractions will just run on a shorter day
Are there specific things in and around Dublin you want to see? If so, take a look at their web site and their hours will be posted.

Have a great trip!