A possible solution - have the bar owners invest in a shuttle-van or 2 to take people home for a small fee.
The fee would cover the wage for a driver, and the fuel costs.
The drinkers would be able to drink all they wanted, thereby filling the saloon-keepers' pockets, and the drinkers wouldn't be driving with a skinful.
Oh, I've just described a taxi-service, haven't I?

Except that in the extreme rural areas described by Capt. Birdseye, there are no taxi-services.

So a little entrepreneurial spirit from the bar owners would ensure that they stay in business.

Captain, what is more likely to keep (American) tourists away is the steep price of everything in Ireland, and the exchange rate. 2 weeks ago it was $1.50 to the Euro. And it's cheaper to buy a pint of Guinness here in the U.S. than it is in Dublin.

Seamus