"Monday will go pretty well. I'm looking forward to the formalities of electing a new leader and deputy leader and relatively shortly after that I'll end up at Government House to resign."
Key said many of the world's leaders have been in touch over the last few days to wish him well.
"Huge numbers, from [Barrack] Obama to Justin Trudeau, Prime Minister [Narendra] Modi, a large number."
O'Connor and Trimble, who tied the knot after first meeting five years ago, acknowledged the Keys' attendance at the ceremony.
"It's an honour to have them here," O'Connor said.
Trimble, who is the sister of Government Minister Simon Bridges - who ran an unsuccessful campaign to secure the deputy PM job and was in attendance - said the afternoon went perfectly after an unexpectedly busy last few days.
"In particularly in the last week, it's been pretty busy," Trimble said. "I feel like I did a lot of the setting up because Simon was so busy."
O'Connor paid tribute to his new wife's help in ensuring the big day went without a hitch - saying he's fortunate to have a partner with such a good understanding of politics.
"She is incredibly forgiving for the amount of time that I have to be away," he said.
"Rachel's come through a political family so understands, which helps. I'm very lucky."
The happy couple had planned to move house tomorrow, making Trimble's house the family home.
But that has been delayed to allow O'Connor to be in Wellington for caucus and the appointments of new National Parker leader and Prime Minister, Bill English, and new deputy leader and deputy PM, Paula Bennett.
O'Connor says both English and Bennett have his support and he will fly back to Auckland as soon as possible to prepare for the honeymoon.
"We leave on Thursday, we're off to London and around Italy for a few weeks," Trimble said.
"We can't wait, it's been a great day and it's going to be a fantastic trip. We're very happy."
