You ask for any advice.
I would humbly suggest getting the bike sent via
http://www.overlanders.ie/ to Bilbao and flying to meet it. By the time you pay for ferries, peage, half a back tyre etc, its cheaper. And more importantly, you add 4 days to your holiday in that you are starting and finishing from where you wish to be. Book the flight well in advance. Drop & pick up the bike in Gorey.
Myke