The points are pretty flat that time of year, but the beachies over the hill can have some good clean waves.
I wouldn't expect to get anything over 3 foot, with most beachies having between 1 - 3 foot, but sometimes it can be flat for a week or longer at a time.
If it is a "true winter" though you may score good, because at this time of year it mostly means Crisp mornings with light offshore winds, Sunny days and the water is super clear.
These conditions will last from say the start of june till around the end of august... But only if it is a "true winter"
Being used to cold water you will get away with boardies and a thermal or woolen rashie, but a springy wouldn't hurt either.