Absolute worst case they’ll get bought by someone. Far too valuable of a company with too many assets to just fold up shop.
This is my bottom line, too. Outside of Tesla, some automakers have finally jumped on the EV bandwagon, but others are dragging their heels. As EVs gain in popularity, Tesla's intellectual property (that is, the designs for their cars, as well as patents and whatnot) will become extremely valuable to the laggards. So if Tesla were to hit serious problems soon (say, if the next three or four quarters were really bad), a company like Ford might snap them up. A non-automotive buyer like Apple or Google is also a possibility, as is a relatively new and unknown Chinese automaker. The Supercharger network might or might not go with the rest of the company, but it, too, is a big asset to the right buyer.
The biggest risk, IMHO, is to a short-term (a few weeks or months) disruption, during which time Superchargers might not charge, we'd see no software updates, and it might become impossible to get replacement parts. That could be a real problem if you happen to get into an accident, or if your car breaks, at the wrong time; but I'd be surprised if such problems weren't resolved in a month or two at the most. There's also the likelihood of third-party suppliers stepping in to provide spare parts, at least for some components and for the more common Model 3.
Keep in mind that, even as Q4 2018 ended, Tesla warned that Q1 2019 would not be profitable. It's true that the losses were greater than most analysts were predicting, but it was a "perfect storm" of issues, and the next few quarters don't seem likely to reproduce such issues. Thus, I don't think it's likely that Tesla will go bankrupt in the next year or two.
