Seeing some very decent JAL premium economy fares from Syd/Mel to London and other European destinations around Aug-Oct 2020 (may be more dates!). Cheapest seems to be Syd-Lisbon return, but can also price Syd-LHR, LIS-SYD on JAL website. Some fares showing on google flights, but seems to be best to use JAL website to see open jaw options. JAL premium is fairly unique in that you get lounge access, and the Tokyo lounge is fantastic. You will also likely have a stopover in Tokyo in at least one direction, but there are certainly worse places to spend a night...
https://www.google.com/flights?hl=en...0*2.GBP.127041