One thing my Mum has had trouble with is opening a Greek Bank account, in fact after one year after moving she is still using her English account and yes its costs a fortune taking larger amounts out of the ATM's as the charges scale up respectively.
The mutually beneficial solution we have found is for my Mum to send me her money by cheque, I then put this into an ISA back here in the UK where it can accrue interest, then when I go to visit I can take out the amount my Mum needs. I can either exchange it here using my Thomas Cook rate or take her the English money, which she may change.
For smaller amounts she still does use the cash machines but so far this has worked well. (and me as I get more interest on my ISA)
Its worth noting that even if your bank offers you free cash withdrawals abroad its still dependant on the machine, much like here, which may charge you additional handling and interest rates and of course you have the exchange rate to contend with.