Public Holidays - Santo Domingo - groceries accessible?

Major supermarket chains such as La Sirena/Super Pola/Jumbo/Nacional open on all public holidays but with reduced hours. Check their websites.

Some shops will be open and colmados will always be open unless the owner has gone away and there will be one near where you are staying.

You will be able to access ATM's at banks, in malls, supermarkets and gas stations etc. but the risk is that they may be out of cash so you may need to try more than one. There are ATM's in SDQ airport in the arrivals hall but there used to a limit on withdrawals to a couple of thousand pesos.

Public taxis will be running as will airport taxis. The Metro and public buses are operating on limited hours and this can be found online.

My recollection is that you are going to be staying in Gazcue, so expect the Malecon and Zona Colonial to be busy later on News Years Day and you can be sure restaurants will be available. La Cadena is probably the nearest bigger supermarket and you will need to check if they are open.

Once again, lennoxnev, you're a wealth of invaluable information. I'll check each of the websites you mentioned for operating hours and allow for attempts at multiple ATMs. Thanks 

That is exactly correct. New year's day most grocery stores are open.  Colmados are open and every bar in the city will be hopping!