What they do is check on HF that the weather OK for Lord Howe. If no-go they turn around and go back to Australia.
If Lord Howe and enroute to Norfolk they use the radio to check the weather. If no-go they turn around and return to Lord Howe which they have checked is OK and land there during daylight hours.
If coming in the from the east side of Norfolk they should check and recheck that the weather is OK and if not have fuel and a plan to go to somewhere that they can land at. Plan B.
That was a major item in the ATSB report.
Again I note that the weather at Norfokk is fickle. Be warned and go prepared with plan B.
The problem with the Baron, above, was that it left Australia too late in the day, it did not have HF, it had no plan to return to Lord Howe in daylight if Norfolk was un-landable.