None of us are thinking big enough about Gigafactories. Tesla needs to break ground on a new Gigafactory every year for at least the next 9 years.
The only way to keep growing battery capacity by say 50% per year over the next ten years is have multiple campuses that can expand by about 10 to 50 GWh per year. Suppose we have 50 GWh in 2018 and grow exponentially to 850 GWh in 2025. Now for 2026 we will need to add 425 GWh more capacity to reach 1275 cumulative capacity. So how do you build out 425 GWh in one year. If you have 9 campuses, each campus could add about 50 GWh. That seems plausible. But if you only have 4 campuses, then each one must add at lease 100 GWh in a single year. This seems unsustainable, if not implausible.
So once you wrap your head around the idea that Tesla needs 9 or more Gigafactory campuses by 2025 and these need to have lots of room for expansion, the question where to build the next GF becomes not such a big deal. Tesla needs to be looking at new sites on every continent. Whether GF2 is in China or Europe is inconsequential because both will be needed in within the next three years and a third one somewhere else. India, Peru, UAE, who knows?