My main issue is accommodation for 5! But looking at Queenstown most accommodates 4 not 5. I'd like a day walk in the country but will it be too cold? Boys want to see a deer farm. Are Hanmond Springs worth it? Some utube clips make it look crowded and just like a hot pool. Larnach Castle is amazing but more a couples get away than a family holiday venue but it's well worth a visit.
If you stay there book a meal in the formal dining room when booking your accommodation. Completely agree with all of the very wise advice above. Re Hanmer Springs. I love the little township but the pools are over-rated. I do say that from an adult perspective In the time you are there you will definitely be able to fit in some walks as there will be some nice weather days hopefully.
Yes it's likely to be cold but as long as you dress for it you'll be fine. Aim to drive and walk after 10am in the morning when the worst of any black ice that has formed overnight has thawed. Is Kaikoura a must? If so then how about this itinerary? Day 3: drive to Mt Lyford and stay 2 days to allow 1 full day on the slopes no idea what the ski-field is like sorry and accommodation will be very limited I would imagine.
Day 7: go through the Lewis Pass we usually advise the drive via Arthurs Pass further south but this makes more sense given your enthusiasm for Mt Lyford and Hanmer Hokitika Gorge stunning on a clear day when not much rainfall or rough weather in few days prior.
Day drive to Wanaka be aware this is a long day and I would get started no later than 9am despite my advice above Day Drive to Qtn easy drive from Wanaka Rest of time in Qtn and fly to Chch from here on day of departure.
