Don't know specific about soya milk, but we were in Ireland (southern) for 2 days recently, (didn't want to leave) and I don't think there isn't anything you can't get there ( is that good gramma). Great place, lovely people. Have a good holiday.

Jenny

One thing I would say, customs are strict, you might not get milk allowed in if you took it with you. Best to check, Irish Embassy are very helpful.