For those keen to catch some winter fronts and don't mind a bit of a drive - there is usually a lot more wind down South in winter then there is in Adelaide.
There's been several weekends this winter when there was kiteable wind at the Murray Mouth (also Goolwa/Middleton/Victor) and Adelaide was dead or marginal.
ALso - the further South you drive the stronger the fronts, sO if you're really keen (or should I say "desperate") for some decent wind then Lake George (and Beachport/Robe area) frequently gets 25-30+knots

and is less then half a day away:
(from Google - Lake George S.A.)