is it even worth doing anything differently for a very short break and the perhaps once yearly trip to the UK?
I have just come back from a weekend in England. Many of the ATMs there charge you to withdraw money, so when you draw cash you are not just paying BOI and their high exchange rate, but other UK fees.
When you use your Irish debit card, the business you are purchasing from will use their own unfavourable exchange rate.
I don't know how much you spend on your trips, but if you are paying hotels, transport, refreshments etc while abroad the savings will be worth getting a multi-currency card.
I travel as often as I can, within Europe and beyond. For many years I have held a Wise debit card, which does not charge an annual fee, and when used to cash withdrawals or purchases abroad enables me to choose the more favourable local currency option rather than bank or merchant exchange rate.
I am notified every time a transaction is made, so would notice a scam instantly, but have never had a problem.
It is very easy to transfer funds from my Irish current account, so you do not need to keep a high balance there if not needed.