New Zealand advice
 

My wife and I will have a week for vacation mid-September after my conference in Brisbane. We were thinking of going for a week to New Zealand, after lots of reading thinking of spending 3 days in the Abel Tasman Ntl Park area on the North Island, then to Auckland and visiting the city and some day trips for another 3 days before back to overnight in Sydney to catch our early flight.

We know this will still be early spring and a bit chilly in NZ plus we burn some time flying, so I thought an alternative would be ~3 days on Fraser Island, then maybe Hunter Valley or some other destination in NSW, we have been to Cairns/GBR and Sydney before so wouldn't put that as a major goal.

Any thoughts on this? I know it is very subjective but that is what travel is about! Thanks in advance for any suggestions.

I reckon you just made a typo; Abel Tasman is on the South Island.

I can't help with your OZ ideas, but IMO September is a fabulous time to visit the SI of NZ. I've done it myself many times.

BUT, I'd not absolutely not try to visit both islands in six days. I suggest you pick either or and go from there.

Yes, South Island for Tasman, sorry. If we decided to just stay on the South Island (which is inconvenient since it takes a good part of a day to get to Nelson no matter how you fly from Brisbane), what would you suggest for the other three days we have available? I am aware of the long driving times so we were thinking perhaps Marlborough and the north end of the SI.

Yes, Picton would make an ideal second base, although if your intent is to spend time in Abel Tasman, I suggest you stay closer to it than Nelson, as in Motueka, Kaiteriteri or Little Kaiteriteri.

I agree! I LOVE Abel Tasman. But bear in mind that it's all about walking and taking boat rides to explore the natural beauty. If that appeals to you, stay in one of the cottages right on the edge of the park.

And ... I second the suggestion for Picton and the Marlborough sounds. I wasn't prepared for how beautiful that area is.

Thanks so far for the advice, we would not stay in Nelson, just fly there and stay somewhere closer as you suggest.

We have traveled extensively, but New Zealand was the most beautiful country we have seen. We did day tours from a cruiseship, but if we could go back we would rent a motor home and drive the countryside at leisure.

Or just spend a week in the North Island. Closer to Brisbane and every bit as beautiful ( albeit very different) to the South Island. With a week you can go north from Auckland to the Bay of Islands or South to the Coramandel, Rotorua and Taupo.
NZ is magnificent wherever you go!

Waiheke is a beautiful day trip from Auckland, also with 6 days you hire a car and drive to Rotorua and Taupo. Or as Kwaussie mentions Coromandel or the Bay of Islands would also be lovely.
IMO Nelson/Abel Tasman National Park is best in the summer but September can be okay might need your coat or jacket but if you are from Wisconsin you won't find it cold! But if that's your only chance to get there then do it. You would have to use up a day getting to Nelson and then driving over to Marahau, where the park starts. The water taxi can take you to a particular beach and you walk along to the next. There are no roads in the park.