If they maxed out the "Tesla Factory" (formerly NUMMI), they'd still need ~100k vehicles/year from somewhere else. GM just announced they're spending ~$1.5B on a 150k vehicle/year plant in China. Assuming the new Tesla factory would be more expensive, since labor cost in the US demands more automation, they'd be looking at ~$2B to build a new facility. Plus the costs from the upgrades at the Tesla Factory.

I have a hard time seeing Tesla deploying $5B in CapEx in the next 5 years when they only have $700M in PPE now and $800M cash in the bank.

When they retool for the Gen III 'Model E', I'd expect about $1B in capital investment to satisfy a production level of ~150k cars/year.

CapEx is probably significant robotics infrastructure. You can't automate everything in the plant. Yet.