Far easier to leave your money in the bank and take a fee free credit card, or if you dont like credit cards, Nationwides dedit card. No hassle for changing money and its safer than carrying money about.
We just got back again got $2/£1 on CC. 3 Adults we averaged $100/day but none of us like shopping. Covered 2 meals a day (don't eat breakfast) gas, snacks, supermarket etc.