We normally try to catch the New Zealand summer every two years so we head to Christchurch NZ to visit family. This time we are going to be leaving in the UK school summer holidays and will catch the NZ winter and it will be a first for me.

I am United 1K and have approx 600,000 miles to use. What we have done the past couple of times is to book in B class and upgrade either using SWU or miles and go LHR-SFO-SYD-CHC on the basis that it has been nigh on impossible to try and book award travel for 3 of us (2 adults, 1 child) to travel on the same plane at the same time.

So - is this my best option (booking in B)? Is there a better way of doing this and still going business/first? Best way to burn up the 600,000 miles? And of course the minimum amount of cash spent to travel business if possible! Thanks.