I have never, ever, ever had trouble driving to and into and around Thredbo (or Perisher) in an AWD with regular tyres. I've been here for 16 winters now, driven in all kinds of conditions.
But that's an entirely different discussion.
I had a similar story until we got hit by two blizzards in three weeks last season. The first one dumped fourteen inches of snow on the car. Took 40 minutes to dig it out. On the drive out we needed chains until just past the entrance to Lake Jindi. You really don't need chains, right up until the moment you do.
FYI, in emergencies you can rent chains at the petrol station. Drop them off at the service station at the bottom of the Alpine Way (next to the caravan park).