Pretty manic, but the standard of NZ accommodation was pretty high last time we visited, so finding places en-route isn’t as bad an option as some places.
Taupo is nice and has a relaxed feel. Scenic cellars used to have a huge downstairs vintage cellar to sift through.
Napier has the most wonderful architecture due to being levelled by an earthquake 80 years ago. I love the place and it’s arguably the finest wine region in NZ
Martinborough town is surprisingly flat, so easy to navigate. Do consider slotting in a lesser known producer in as well, as there can be some good stuff outside the ‘names’
Wellington has transformed itself, from being a little dead 20 years ago, to being very vibrant with one of the world’s great coffee scenes - we failed to find a place serving anything but very good coffee, and that included some fairly standard cafes. Regional Wines & Spirits near the basin reserve is well worth a look for wines. I’m told the national museum is very good indeed.
Overall it looks a little rushed, and it’s worth challenging whether the days represent full days, or also take in travel time. If the latter, then some of these slots may be much too small. e.g. Napier to Martinborough is a long enough drive, so if leaving Napier in the morning, it would be more like half a day in Martinborough, plus you’d be very tired. 4 wineries in half a day just sounds like it wouldn’t do them justice.
Might also be worth (when in Hawkes Bay) looking at Church Road (despite it being the huge Montana/whatever they’re called now), plus Mission Estate which both offer significant history. In the case of Mission, they also still have a rather unusual set up, but the quality of the Jewelstone range can be very high indeed.
Do also try the various fish, many of which will be as new to you as they were to me. Shopping in a fishmongers had me flabbergasted for the variety and wonderful value for money. The fish and chips are also typically very good, and typically cooked fresh to order. For lunch, well worth considering one of the many pie shops that are often very high standard with a big range of fillings - a very tasty and filling pit-stop option.
Finally do take the time to stop and chat to people in the smaller towns, as they are often very willing to chat and take a genuine interest in visitors - not in the way of tourist-farming, but out of very natural interest.
regards
Ian