if you fancied taking the train into Dublin, then you should consider the Glenroyal Hotel in Maynooth. Right by the train station and you can get off at Drumcondra and walk to Croker. You can always get the 66bus into Dublin just a few minutes walk from the front door of the hotel.
The River Forest Hotel/Leixlip House Hotel in Leixlip are also close to Confey train station. The Springfield hotel in Leixlip has a bus stop outside also.
PS - I travelled from Newbridge on the back roads towards Clane/N4 two weeks ago when the hurling final was on and there was quite a lot of traffic heading south. Seems most wanted to avoid the N7.