6 Week Itinerary from New Zealand - Help plz

Just as an aide in planning, it is usually helpful to count nights in a location, not days. Due to travel time between places taking 1/2 to most of a day, 2 nights in a place means 1 full day there, plus a half day on arrival or departure day. Also, in laying out your route, I would first check out the best ways to go from place to place (air, train, bus, ferry). Knowing the range and cost of your transfer options helps in planning.
Overall, your must-see cities are ones I would choose also. There is a reason London, Paris and Rome are the top cities to visit. And going in Europe's winter season will cut down on the crowds you would encounter in the summer. (I confess to having a special place in my memories for Vienna.) Have a wonderful trip to Europe!

I love Greece and have been there three times with another trip planned next year. But it is out of the way and wonder if you would not be better off using the nights elsewhere. I have been to Crete and spent 11 nights which was not enough so the idea of going to all the trouble of flying there for three nights in off season especially seems to be worth reconsidering.

I know you are in your 30s but even when I was I would have found the pace you are proposing too much to keep up for 40 days. At the very least I would add an extra day for laundry and not doing too much in the middle of your trip.

I think starting with London is a good idea but would add another day since the day you arrive will not be a real day. We spent 5 nights in London our first time and found that to be a good amount of time. But we moved on to Bath, England not Paris but only you know how much you would enjoy one urban destination after another. I would consider adding more smaller destinations to complement the blockbuster cities.

I would choose Option 1, allowing you to acclimate in an English-speaking environment. For reference, I was 69 when I first went to Europe and don't find your pace too fast--you might, but I'm just saying you won't know until you try. I've spent over 100 nights on the continent now and still would go this fast in my 70's.

I second the notion of adding a night to London at the beginning because there will surely be some exhaustion and/or jet lag leftover from the trip. Just consider the first night a time to crash. Whatever your first destination is, add 1 night for getting yourselves together. As for Greece, you decide (I haven't been there yet, but very much look forward to it). Based solely on what I read, Crete seems like too much travel chaos for what you would get out of a short visit, so personally I'd reassign those three nights.

For additions, consider Berlin. It's not typical Germany and isn't especially charming, but it would introduce you to the country and is extremely interesting. It also has a young energy that's very attractive and that you would no doubt enjoy. (If you did this, it would mean flying from Athens to Berlin, then on down to Prague (also Germanic but quite different) and Vienna, a great final stop. If you don't want to do Berlin, or want to squeeze in even more with your extra 5 nights, give some real thought to Spain. Madrid is a modern city, also quite hip in some spots, with an assortment of interesting day trips possible. Barcelona is a different vibe altogether and Mediterranean in spirit with unique architecture. The down side of Spain is that this would require another plane trip from anywhere on your current itinerary.

Lastly, regarding the comments about mixing in some smaller places: for a first trip, and a fast-paced one at that, I would keep your lodging in major cities near transportation and then if and when you are tired of that, there are day trips you can take either on your own or with a tour group out into the countryside or at least smaller cities.

Good advice above about starting to figure out the transportation and letting that govern some of your planning. Also start tracking what you actually would want to do in or from each city, and guesstimate how much time each will take. When you don't know, you can ask on this forum, under the appropriate country.

I agree that Greece/Crete are kind of outliers, and would save them for another trip (I had my first Europe trip at the age of 30, for four months, luckily! and still didn't get to Spain, Hungary Greece or Scandinavia). Putting in some no plan/do nothing days 2 or 3 times will rejuvenate you and give you a chance for laundry and just goofing off. I would take your Crete and Athens nights from option one and add 2 each to London, Paris and Rome. You can do a day trip or overnighter from each city (London...Bath, Windsor, Oxford, Stonehenge; Paris....Reims, Chartres, Lyon, Beaune; Rome....Naples/Pompeii, Ostia Antica, Villa d'Este, Sorrento) Lots of choices for day trips or overnights from the big three, plus you cut out a couple of long travel days.

As an aside, I understand the departure tax from London is quite a bit higher than from other cities, so flying into London and leaving from Vienna seems to be the better option. Best of luck and have fun with your planning and with the tripo!