These "disaffected" Republican's, as you call them, who've become libertarians, are minuscule in number. They have no power or influence in American politics. Libertarians are of no consequence in the modern political arena and frankly, never will be. And there is no "libertarian problem". They're an annoyance at best.
Republicans haven't left Reagan either. Reagan's legacy as a great conservative Republican remains safe. Reagan is a conservative hero and not a libertarian hero. If libertarians want a hero they should look to that old fart Harry Browne or the looney, Ron Paul.
If libertarians are "minuscule in number" and "of no consequence," why are some many Republicans shouting that libertarian votes "cost" Republicans several elections?