Wife and I travel in Europe a lot, and the most economical way to have access to currency is with our Wise Card.
Prefill any currency from your own bank. Minimal ATM charges, and best exchange rate.
Never had a problem anywhere in UK or Europe.
We have had the card for a long time, and top up currencies when exchange rates are are in our favor.
We carry three currencies on our card. US$, GBP, and Euros.
Wise, Formerly TransferWise: Online Money Transfers | International Banking Features