We stayed in Portrush one Monday night in May. The town was dead and most of the restaurants and shops around the main bay were closed. I'm not sure if that was a function of the day of the week or the fact we were ahead of tourist season.
We loved visiting the Giant's Causeway and the Carrick-A-Rede Rope Bridge that day. Both involve a lot of walking.
Anvershiel House was the B&B we stayed in, mentioned in a Rick Steves guidebook. We had no clue it was a "no host" B&B. We never laid eyes on a soul until we ran into a couple other customers at breakfast. You check in with a remote-access key, never meet a host, and must fix your own coffee, tea and breakfast, moving back and forth from small refrigerators in the breakfast room and a larger fridge around the corner. It was the least personal B&B I've ever stayed in. They did have a few on-site parking spots.