If you are going to somewhere that freely accepts credit cards (like supermarkets in France), then I can recommend a Post Office Platinum credit card - very close to inter-bank exchange rates and no transaction fees.
In 6 months in France, I've used about 300 Euros in cash, all the rest on MasterCard/Carte Bleu.
Most of the cash went on taxis, but since I got mobile data working, Uber avoids even this need for folding stuff.