Here you go Jez,
This is the best and shortest run that you could without going to dream land and stating that you can run 45deg off the wind. All these maps are for a SW wind, if the wind goes to a WSW the run would be shorter in distance but the legs would be longer on the one tack and SSW even worse.

The total is 52 km with the longest being 30km and 30 deg off the wind.

Hope your Right leg is fit.
This one is more real world, a bit squarer to the wind with short off the wind runs back into the swell for control. The longest run is 14km and total distance is 78 km. Your right leg is still going to hurt.

Different people will take different routes but the physics and the swell remain the same.
Matt and I tried to stay together on the Lake George distance trip but we found it very hard, found the same running swell lines with others at the Pit.
Do a short run to Rickets (12km on a SW) and back or do some long runs from Rye to Safety Beach (16km on a NW) which I have done and is great fun and safe and you can extend it to Mornington 25km
Please do a trial run with a small number of fit people with a support boat that if it all goes pear shaped will not attract the attention of media, authorities and make our life so much harder to run organized events. Yes be a rebel and do something amazing but don't do it stupidly without careful thought for everyone else.