Using current technologies, this can be done within a year, but at the expense of the price tag ... it will cost no less $ 12-14 million
In fact, the Chinese wall was built for several centuries and not entirely, but in parts. Who exactly? Most likely the Mongols. The fact is that all the loopholes in the wall are turned towards the territory of China. A fact that is still overlooked.
It seems to me that the process of solving all administrative, bureaucratic and political issues would take 2 times longer than the first construction. And then look for more suppliers :)