70 mins is fine D to I so long as your flight isn’t late. Qantas runs an airside bus - from domestic terminal gate 15 or something like that straight to intl. you’d still have to redo security screening as intl security requirements are different to dom ones but it shouldn’t take long as it’s dedicated to the people who are taking this bus.

if you are on low frequency markets where you cannot be rerouted you might want to have a longer connection. QF otp in April was <50% due to staff shortages