For Saturn, or any of the showpiece planets, and the Moon you do not need dark skies, because they are very bright. Barlowing the 9mm probably gave you too much magnification for the conditions. You should be able to see the Cassini division from here most nights (when not cloudy
) if your mirror is properly cooled. Try the 15mm eyepiece first (that's enough to begin showing Cassini) and then the 9mm. Then barlow the 15mm if seeing allows, and try the barlowed 9mm on rare nights of exceptional seeing.
Falls Creek is 1.5 hours. But you said 20 minutes so then just take the Freeway as far as you can go, and find a reserve without lights.