I live in Ireland and generally have no problem low carbing.

In places with set meals, imply that you are diabetic and/or allergic to gluten, and ask for meat to be served without sauces and for green veg or salad instead of anything you don't like the sound of. They are used to it. Cheese plate instead of dessert, and whipped cream in coffee.

The Irish breakfast is a good start to the day, as long as you ruthlessly dump all the toast and beans etc, and stick to the eggs, bacon, sausage, mushrooms etc.

Every half-way decent restaurant will serve you steak, chicken or fish with salad or green veg. Even the fast food places now all have chicken salad as an option.

Most pubs do a carvery lunch, so go heavy on the meat etc, skip the spuds.

Carry a packet of nuts, or a ringpull tin of fish for those very rare times when you are really doing badly, but honestly, you should be fine.

Guinness, unfortunately, is lower carb than most beers, but still pretty high.