Position outside the circuit to join Downwind Left Hand - there is no other option
Yes there is, you are already on an extended base leg (almost) so what's wrong with joining base leg ? (assuming it is not unduly busy)
It all depends on how busy the circuit is, there is no definitive answer. If the circuit is empty, or someone has just reported finals to land and know one else is flying then it would be common sense to join base leg resulting in a safe and expeditious join.