From Sa and wife want me to retire on east coast. Sail around 100 days / year here with 5m or smaller. Does Gerroa have that consistency or somewhere else in nsw? Happy to halve it for good waves but less than once a week average seems a bit like hell to me...

Easy answer is no. 100 days puts you in WA regularity.

However, I would say Illawarra area most consistent in NSW for
waves & wind. Coffs coast pretty windy with a variety of weather
but not much good for flat water.

Illawarra gets crazy westerlies and good southerlies.

Gerroa excellent for funnelling NE but needs S/SE swell and gets
really flat after NE blowing for a couple of days. This is all common
knowledge and there are plenty of other posts on Gerroa and other
spots to sail such as Werri 10 minutes away! Water a few degrees
warmer than SA I guess.

Jervis Bay and Sanctuary Pt get strong NE as well. Just read that
Hyams beach is a summer 'nightmare' due to tourism to
experience the white sand.

Gerroa was a lot of older beach shacks and holiday houses, the
inevitable property drive means some houses now over $3 mill
and more houses around Gerrigong although still relatively
under-developed compared to Sydney.

Road is good to/from Sydney, only slower spot is through Albion
Park rail if you ever want to drive to Sydney?? Probably 90 minutes
or less to south Sydney.

Tomp is spot on I. His summary Winter in Gerroa is very quiet and cold. Wind is good owing to local topography but swell less consistent

Info much appreciated..

If you can be flexible and are prepared to drive you could do a lot of sailing around the illawarra. I'd say I averaged 2 wave sails a week over winter, nothing epic but you'll get wet. Add the lake or light wind sailing alongside surfing and a bit of stand up paddle and you'll be in the water every day of the year. If you're strictly wavesailing only then it may not be the right place for you.