... Ireland has less than a fifth of the population density the Netherlands has. They don't particularly strike me as a "jam packed horror".
There's significant danger that rising oceans and a major storm could kill millions. That sounds like horror to just about everyone.
And Netherlands has adjacent countries not so dense as itself with forests and open space to adjourn to on weekends for sanity. Ireland is an island.
Your assessment is extraordinarily inaccurate.
"insanely crowded"?
Then why is the majority clamouring for more homes to be built? Property prices are climbing, not because things are too crowded, but because there aren't enough houses.[1][2]. Surely if it were "insanely crowded" here there'd be more of a popular pushback saying "where are we going to put these new houses?". Let me tell you: it doesn't exist.
The Irish government is going to great lengths to encourage new house building to meet the demand.
Ireland is famous for for manufacturing land out of the sea? Really? Well you're going to have inform this Irishman what you are referring to. The only things I can think of is the creation of Bull Island -- which was an unintended side-effect of the building of the Bull Wall, a successful project to dredge Dublin Bay undertaken in the early 18th Century [3] -- and various land reclamation projects around Dublin Port over the past 300 years, which a quick google search will inform you were more to do with planning permission than overcrowding.
For a country which is "insanely crowded", someone forgot to tell the population that. Add to this the population density facts which other commenters have provided, which you disregard and I can tell you that your information sources are lying to you.
[1] http://www.irishtimes.com/news/environment/review-of-the-yea...
[2] http://www.irishexaminer.com/business/features/shortage-of-h...
Wait, did I say interesting? I meant "horse manure". That is an empty country, with plenty of room and remarkably little need for the sort of xenophobia you've espoused in this thread (a xenophobia that no one I met in Ireland seemed into, either!). And I don't think HN needs it, either.
Ireland is almost empty of wilderness and has scant backcountry. Even the mountain ranges have a very few trails backed by industrial tree farms. Most of the supposed forest left is so tightly controlled that the wave pattern of regularity produces moire patterns in the trees. All the life, nature and interest is squeezed out.
There's certainly no place left to seek extended solitude or homestead cheap land. The youth of the countryside are leaving or escaping to cities. I'm glad the nearly-indoor controlled experience of the roads was nice for you, but Ireland is full and bursting at the seams. More people will only make it worse.
If it is any stronger in Ireland, it has much more to do with how bad the infrastructure is in Ireland and how Dublin-centric most investment is.
"A manufactured experience professionally landscaped by traffic engineers"? You give our government more credit than it deserves.