Clearly there is a “do nothing” option when it comes to a trade deal with the EU. WTO rules would apply, which has hardly restrained China, USA, India, Brazil and many, many others from trading with the EU from outside the single market.
NOTE:- The Single Market is NOT free trade, it is the very opposite.
However, there is almost certainly a win-win for the EU and the UK if a deal can be struck. And it is good to see that New Zealand has offered to help. They have experienced trade negotiators that the UK no longer has and they have offered their services.
There are those in the EU who have stated publically that “there must be consequences” to the UK for Brexit. They wish us ill, which is in stark contrast to so many around the world outside the EU. In 1982, New Zealand lent us a frigate during the Falklands war. We had no such support from Europe: France supplied Exocets to Argentina, and Belgium refused to sell us ammunition.
With Korea, New Zealand, Australia and the USA (excluding Barak Obama) all expressing interest in arranging trade deals with the UK, than goodness we are unshackling ourselves from the EU.