Are you specifically keen on one of the wineries, or do you just want to see a NZ winery or two? There is actually a phenomenal one (Amisfield - search this forum for threads about it) right outside Queenstown that can let you cross off that bit and not spend as much time trying to hop between all the cities you've got on your list. We had a great lunch there and bought a couple bottles to help keep up lubricated over the rest of our trip.

I'd fly to ZQN on Saturday morning as suggested above and then drive straight away to Te Anau. You can be there by noon and actually relax a bit and recover from the jetlag. Go to Milford on Sunday and then head back to Queenstown (and Amisfield) or even up to Wanaka - similar physical features without the over-development that I felt Queenstown had. Or do Amisfield on Saturday before going to Te Anau, but still Milford on Sunday.

And I'd do the glaciers instead of Wellington and Picton, but that is mostly because I absolutely LOVED the glaciers, not because I have any knowledge of or experience in Wellington and Picton. If you spend the time over on the west coast there you can also hit up Gillespie's Beach, which is also rather beautiful.

I'm not sure how the weather is going to be this time of year and if it will make a difference versus what I saw, but I really am a huge fan of the glacier area.