Welcome to Just Answer. I am here to help you resolve your tax and finance concerns. Please feel free to ask anytime you need extra help.
There is no provision in the law for "transition". You will not be a SC resident until you actually move there. Until then you are a GA resident.
However, all is not lost. The mortgage interest and real estate tax deductions apply to a first and second home. Therefore, you will be entitled to claim these deductions for both homes on your income tax returns. While this will not avoid any taxes it will help reduce the income tax burden you are faced with.
There is one more paragraph I would like you to see:
The easement, to be of the nature and character herinafter further expressed, shall constitute a binding srvitude upon said Premises of the Grantor, and to that end Grantor covenants on behalf of itself, its successors, and assigns, with Grantee, its successors, and assigns, such covenants being deemed to run as a binding servitude, in perpetuity, with the land, to do upon the Premises each of the following covenants and stipulations, which contribute ot the public purpose in that they aid significantly in the preservation of the Builsdings and surrounding land area, and which help maintain and assure the present and future historic integrity of the Buildings.