Check what is the currency exchange fee - while you might not pay for withdrawal, they can still add a few % of the exchange fee (that’s at least the case for some of Polish cards).
Schwab's currency exchange fee (via withdrawal at non-US ATMs in local currency) has basically been the spot rate in my experience, for a decade or more that I've been using it. And there's no other fees so it's basically free forex (for small amounts I presume, they're not going to let you do that for $1M I bet).
How do you find out what exchange rate they use and how it compares to the spot rate? I have cynically assumed that they make money on this (despite claiming “no foreign transaction fee!”) but never knew how to check one company versus another.
I google “USD to GBP” or whichever currency right after I get the money. My BoA/Chase credit cards also give me basically spot rate conversions. Although this article explains why it might not make sense to use that number: