As I mentioned upstream, the Supercharger network is not a viable profit center. It is primarily a marketing expense for Tesla. Let's just disregard the construction costs and focus on the ongoing operating costs. Lease payments are made on most locations, while repairs, electricity charges and property taxes are paid on all of them. No white knight is going to acquire this network and then figure out how to install a fee-based structure, maintain the units anywhere near as well as Tesla does today, and make a reasonable return on their investment.
It is not clear just how valuable the Supercharging concept is today. There are no competing manufacturers out there that have long-distance BEVs in the pipeline (at least to my knowledge, save the Bolt.) There are too few Teslas on the road. So, the tangible Supercharger assets are probably not even worth NBV in a bankruptcy sale. The intangible assets are likely more valuable than the hardware. However, tomorrow might be a different story. If Tesla goes under in 5-6 years, there will be many more Teslas on the road, and there will possibly be a few conventional manufacturers who have entered the fray with their 200-300 mile BEVs. Then, a third party might feel that there is enough current and future demand for Superchargers. Accordingly, then the infrastructure along with the patents will be worth a lot more as a money maker.