G'day markiz,
Good question, I know that some companies honour international warranties, but not to sure about Gigabyte, if you can check the warranty card that comes with the GPU, (I am sure the sales assistant will let you) see if it has a world wide warranty on it. I purchased an 'Omega' watch & it comes with a lifetime worldwide warranty.
If you can try & contact Gigabyte.
Maybe the big guys on this forum, will know better.
Ben.