When I was back to Canada for a few days earlier this year I went and opened an account at the Bank of Nova Scotia specifically for being here, for Scotia isn't my regular bank. Then I email transfer money as needed from my main accounts on the internet to this new account. Reason for the Scotia bank is that they have a bank in Puerto Plata, Sosua and Cabarete which is convenient for me.....and no charge for withdrawals at these ATMs. The present limit for a withdrawal is $10,000RD. So I guess it depends on who you bank with presently and if this idea is worth it to you.
I also asked when setting this up about having to notify them about being in the DR for example using a bank ATM card, and was told this is unecessary. But as stated above, it is always best to notify about your CC so you don't get denied a transaction.