Cabot Lodge is a 2.5 hour drive from the Queenstown airport. Most international flights fly into Auckland, and there are numerous domestic flights from Auckland to Queenstown daily. I believe helicopter service from Queenstown direct to the lodge can be arranged by the hosts. There is also a local airport close by for chartered flights.
The lodge does not have a restaurant for non-guests - breakfast and dinner are just a small affair in a large kitchen/dining area prepared by the hosts for the guests. They always have a meat entree and they served us lamb and venison from the farm. Not sure if the vegetarian option is always available but I did mention that I was vegetarian and a vegetarian entree was always available during our stay.
I booked our suite on their website
https://www.cabotlodge.co.nz/, and they required a 25% deposit which can be paid using credit card. At check-out, credit cards are also accepted.