Thanks DeltaT. Yes - obviously subject to fuel.
I know there's a 2 approach limit in the event of a comms failure (and you have to start your 2nd approach withing 1/2 hour of your expected ETA), but looks like my memory failed me with regards to the rest.
Not sure if it's never been an SOP or if it changed at some point. Can definitely remember reading it somewhere, just not sure where (not what it applied to).