The address you use is the address that the CRA will contact you at. So you should put in your current address. In TurboTax Online there is a question on the top of the Contact Info page that asks “Is your mailing address outside Canada?” – answer Yes to that question. The box names will stay the same, but it will allow you to put anything in them, and not give you errors.
FYI: You won’t be able to NETFILE with a non-Canadian address.