As far as I can tell, the local bishop's dispensation from obligatory abstinence from meat on Saint Patrick's Day when it falls on a Friday of Lent, does not release from the obligation to Lenten penance or from the obligation to Friday penance (applicable throughout the year). So, for me, the most practical thing is to just not eat meat anyway.
Perhaps an exception to all of this would be in a parish named after Saint Patrick which would have the special privilege by law to celebrate the feast as a solemnity, in which case all of the normative penances would, perhaps, be trumped, by law, by the solemnity.
Solution: Declare Saint Patrick's Day a Solemnity in the diocese in perpetuity, which would eliminate all of the prescribed penances and free all the faithful to celebrate that day without restriction and would also eliminate this yearly charade of ambiguous dispensation.
Beannachtaí na Féile Pádraig!