Welcome to my forum. Rather than ask what is open (which could involve whole book!), perhaps a better way to determine it is to Google the places you are interested in. For instance if you Google "blarney castle opening times" you will go directly to their page telling you. It is no sense listing places that you don't want to see or have no interest in. I do list opening times in my book.
Yes, it is more difficult finding B&Bs and even guesthouses at this time of year. I am currently working with a client who is finding out that many places close mid-Nov or even earlier.
Let me know if you have any other questions or I can help with an off-season trip.
I just read an article that said the Carrick-a-Rede Rope Bridge would stay open all winter this year, as an experiment. :) I think I will wait until it's warm, sunny, and NOT windy to try this (which means I may never walk across it!)
__________________
May the light be your guide and the darkness be your comfort!
I saw that article too. It is good news for those visiting No. Ireland in the off-season. I was there on a perfect day and did not have the courage to cross Carrick-a-Rede rope bridge. My husband did it and said it was a piece of cake. I'd rather have the cake!