Most European countries have surprisingly strict visa requirements - and those apply to Americans as well. Unlike a short holiday trip, you can't just move because you feel like it!
The most likely path for the HN public is probably a "highly-skilled worker" visa, but that requires you to have a sponsoring employer in Europe - which means you won't be getting that fancy American salary. And you'll also have to pay local taxes...
If you know of one that does and is hiring, please share...
I think they stay for a few months. Maybe they just don't tell their company and the company still think they are working in the same place.
edit: burn karma burn
However, it's difficult to proceed to a residency permit in this situation, and you can't join the national healthcare system.
And, if they do, they might have legal issues brewing they are not aware of.
I know people who manage to do this, but it's difficult, and not really worth it unless you have a seriously amazing job.
Not sure about family, but you can get new friends here. When I go to the office, on my walk back home, I often pass by some very nice pubs overflowing with extremely happy and friendly people, and that is when I leave at 17:00.
You'll also get nice things like the metric system. And, in Ireland, one of the sanest political systems on the planet. It's so sane it's almost boring.