We drove 0.5km when pinstriping in a 200m overgrown section led us to park, as we thought it would only get worse. It turned out that we could have continued for another 2km in our Subaru Outbacks. The cross ditches get deeper but also longer, so still doable with SUV clearance. In between them the road is open, flat and smooth - for ~1km it almost feels like you could skateboard it!
In the last 1km to the creek washout the ditches are much more challenging and the road is much more degraded and overgrown.