We are going to use ICN as our back up. We are living in Korean at the moment anyway, so having to leave and return here won't matter, at the end of the DONE4 we can visit friends here, and there are usually cheap D class fares with QF via NRT, about $1200, to get back to Australia if needed.

CMB is much cheaper, even when adding the cost of getting there. I hope that we don't have to use plan B, but it is there if needed!