If you can't make money on 200 passngers travelling towards Cork (way more than the average load on a normal Dublin/Cork service) and 95 travelling on an ICR with minimal additional staffing costs then you won't be making money on near anything you care to run.
Having said that, Irish Rail are slow to publicise their special services and now tend to ignore many events - there were no special services from Waterford for the Munster hurling final in Limerick despite there being plenty of demand.
Yeah fair point, I think a min of 50 or 60 is what they require but there is no excuse in using "no demand" on other routes when less than 100 board a train to Galway. Waterford or Sligo could of matched or exceeded that.
I completely agree about the Munster Final, they could of filled a couple of ICR's on the South Tipp Line but it was never going to happen.