OliverM3: I've phoned Vredestein regarding their Space Master collapsible spare. No applications for Tesla. I've spent plenty of time online, searching for an older/used one, but the risk there is age. There's also the wheel fitment issue, probably would need an adapter of some kind.
The risk of placing the tire in the frunk area (liner removed) is obvious: it has to clear the AC compressor, so it would require a bracket of some sort. The greater risk is a frontal collision, and the unknown havoc a spare would wreak on the car. I quickly decided the risks are too great.
I have the Modern Spare. I can lay it down in the deepest rear well, lying on the "crossbeam" between the wheels. It sticks up, of course. I've considered cutting out the flooring to accomodate, and just living with the tire bulging up, but...not a compromise I'm willing to make. The other option is keeping it strapped vertically, behind the rear bumper, but I'm not sure the hatch would close.
Several different discussions at once here. Those that say, "plug/patch/compressor." and those of us that live on the edge of civilization that would be royally screwed by a blowout. Of course, the additional compromise of the Modern Spare is distance. It'll get you to civilization (such as it exists in places like West Texas, AZ, NM!!!), but then the inconvenience of waiting for a replacement tire causes a 2-3-4 day delay.
A full-size spare/wheel is the best solution, but damn, it takes up a lot of space. (Unless I put it on the hood, under the longhorns!)