Well, it depends on a lot of initial conditions that outsiders can't see. If Tesla wants to throw up a steel frame building in an already empty field in Texas or Oklahoma, that's not hard to do. It would take a few months. And during the Model 3 production ramp up, Tesla put together an entirely new assembly line using on-hand spare parts in a matter of days. So if they have an entire Model Y assembly line sitting in storage rooms in California, Nevada, and New York, which very likely they do, it might only take a few weeks to truck all of that to Texas or Oklahoma. Of course that completely ignores quarantine complications. Which might actually help Tesla. Right now, red states are so eager to get positive "restart the economy" news and millions of recently unemployed people are so eager to get jobs that Governor Abbott of Texas might cut mountains of red tape to green light whatever Tesla needs. I would say it's totally feasible for Tesla to be producing Model Y's from a new facility in Texas by the end of 2020. Certainly not at high volume. Potentially from a tent in the parking lot of an unfinished factory building. They've done it before.
