I'm again delighted to hear about your walking/cycling trip along the Wild Atlantic Way !
Usually, tour operators, guides and B&B's can arrange to transport your luggage between your night stops for a long-distance walk or cycling itinerary. You could for instance contact companies such as Hillwalk Tours
or Green Marble Cycling Tours
to see if they offer tailor-made itineraries with luggage transfer.
If you'd like to cover important hiking trails like the Kerry Way
, the Dingle Way (Co. Kerry), or the Great Western Greenway
(Cycling trail in Co. Mayo) for instance, their websites have plenty of tips and suggestions to organize the transfer of your luggage and find accommodation.
I hope this helps. 😊