Worked out well :-)

Asked at checkin if could upgrade with miles and she offered to Op-up me if I left family in Y. tempting as it was, would have been longest 3 weeks of life in Australia. Offered to pay for 4 seats with miles, but she said if I bought 3 they would give me 1 free ;-)

Kids loved it - they in for shock tomorrow when 14 hours in Y to Brisbane as miles now exhausted.