What time is your boat on the Monday? I'd be looking at staying somewhere up in the Wicklow hills such as Lauragh on Sunday evening then dropping down into Dublin for your boat on Monday morning.
There again, you may prefer a night in the city. Give us a wee clue here.
Hi Aidan, we hope to stay in the city Sunday night and have a beer or 3 then get up early-ish for the ferry Monday. A small place where the bikes are safe near the center would be ideal