Seriously, ex-PD voters and Cóir voters are two extremely different breeds. I don't think anyone with any knowledge of both groups would worry about Cóir filling the PD's niche.
Given that the term "far-right" can apply to economic liberals as well as to social conservatives, it is too vague a descriptor to be meaningful.
On the economic front, I would argue that the seeming economic liberalism of the last decade was merely an illusion. During the boom years, the allegedly "right-wing" Fianna Fail/PD government enlarged and enriched the public sector to insane proportions, poured umpteen billions into the black holes of public heath care and education, and increased welfare at an implausible rate. We now have 85,000 more public servants than we did in 1999, and a public wage bill that has risen by €6 billion a year over the past decade. Unemployment benefits have risen by €80 a week since 2003. Right-wing? Hardly. A genuinely economically liberal government would have reduced the size of the public sector, opened the education and health markets to vibrant private competition, and weaned long-term welfare dependents away from the public trough. But they didn't do that—and now we are in a right old mess because the revenue no longer exists to fund the government's fiscal recklessness.
Those who argue that Ireland is becoming more socially conservative perhaps don't recall the days when it was still in the iron grip of the Catholic Church. It's not really all that long ago that victims of domestic violence could not divorce their attackers; that a family needed the Supreme Court's permission to take a raped child abroad for an abortion; that students were being arrested at their universities for the crime of handing out condoms. It's nothing like that anymore, at least.