There are a number of Airbnbs available in Wanaka which can be booked one year in advance.
The Glendhu Bay Holiday park is located less than 1km to the wedding venue and about a 15 minute drive from Wanaka. This is a great option for camping, campervans and cabin rentals.
Exploring New Zealand with a camper van is an excellent choice, providing the flexibility to move around effortlessly. Numerous holiday parks in the South Island cater to camper vans, and several rental companies, including Maui (linked below), are available. It's advisable to make reservations well in advance, as they can be fully booked up to a year ahead.