https://www.2degreesmobile.co.nz/help-and-support/broadband-and-landline/broadband/amazon-prime-video/ seems to indicate this is possible: "Cancel your current Prime Video subscription / Wait until the end of your current billing month / Then you can sign up to Prime Video again (you can use the same account and email address if you like) to get a year on us."

[I had to read this section to 2degrees support after being told I must sign up with a new Amazon Prime Video account]

To confirm whether I can keep my existing account and watch list I asked Amazon Prime Video support this question:

"I wish to keep using the same account with my existing watch list.

"Can you please confirm that if I let my membership expire on XXX that I will be able to activate/link the 2degrees offer to my current account and keep my existing settings and Twitch Prime subscription."

Their reply does not appear to answer the question:

"Existing Prime Video customers must cancel their current membership in order to qualify for the offer. Once their membership is cancelled, they can contact the relevant external partner to add Prime Video to their existing non-Amazon account."

I have an existing Amazon account. I don't see how the relevant external partner (2degrees) can add Prime Video to my existing NON-Amazon account.

Thanks for any further clarification!