I agree, ATMs with euro will have extra fee, as euro is not Polish currency and they must earn somehow for themselves. Especially at the airport it must be expensive.
Check Euronet ATMs
The Withdrawals is executed free of charge by Euronet 360 FINANCE Limited (E360F) with its registered seat in London and it is available only for cards issued in Poland to accounts in PLN. The card issuer may charge fees for withdrawals executed through E360F, especially in the case of cards assigned to accounts in currencies different than PLN. Upon withdrawal floating exchange rate set by E360F is applicable to each withdrawal individually without it being possible to raise any claims against the card issuer and the payment organisation under whose auspices the card has been issued. An exchange rate is displayed upon choosing the withdrawal amount. The regulations are available on the screen and the website: euronetpolska.pl
here is list of ATMs with Euro in Warsaw:
euronetpolska.pl/index.php?m=maps&m_2=results&id=254&district_id=0&city_id=2&street_id=0&service