"Buy a big farm in the Americas and start a Gaeltact there."
actually, if you remember...
http://www.gaeltacht.ca/index_files/Page531.htm ...alright, it's not quite what you meant, but still...
as far as the German example, the generation that had last seen a united Germany had not died out - that makes a big difference. They were divided against their will, and saw reunification of the country as a return to what was "supposed to be"...would such a reunification have been possible if the country were divided for a full century or two?
The Irish people "willingly" gave up their language (albeit with an economic gun to their heads - hence the quotes), and the people being asked to speak it today, by and large, do not view it as returning their lives to better times, indeed they, their parents, grandparents, great-grandparents (and perhaps even farther back) were all monoglot english speakers.
It doesn't mean its impossible, just extraordinarily unlikely. If Ireland can even return self-sustaining stability to the language after how far it's dipped, they will be the first country in history (as far as I've been able to find) to have done so successfully. The only other possible contender for that title is Israel (from 0 speakers to a nation in two generations), but as has already been observed many times - there were other factors aiding success there which would not apply to the Irish situation.
It's a race against time...will the key be found before it's too late?