Just my 2 cents, but if questioned, I'd just explain that my credit cards offer free exchange rates which is cheaper than trying to exchange your money at a bank or paying international bank fees every time you need to use an ATM.

Also $600 is more than enough for food and entertainment for over a month actually. Just shop at stores like Aldi's (you can view their advertisements online to get an idea about food costs). For eating out or movie discounts use sites like slickdeals.net, groupon.com, livingsocial, etc. They often post Uber codes there as well. Many bars offer $1 beers on slow days, so just try to plan your activities for those days vs Friday and Saturday. Also, I have no idea where you are traveling from, but don't forget to account for tax + tips which aren't included in the menu price.