Getting sufficient power for a legacy type Supercharger at remote rural sites is certainly a challenge but is a challenge that needs to be resolved as the network expands to lesser populated areas. Batchawana Bay is a good example of this. But we have seen an example of one solution in the Deep River SC discussion, page 6.
Supercharger - Deep River, ON
Now I'm not saying Tesla should buy and deploy these but Tesla could no doubt build their own higher power and larger capacity equivalent quite easily albeit probably in a 20ft container. If there is sufficient power to run two HPWC at 80 amps there is certainly sufficient power to charge a substantial battery bank (perhaps as much as 4 or 5 powerpacks). Perhaps inverter limitations would limit the chargers to the 72kw "Urban SC" size but even that would be far preferable to L2 charging that tops out at 20KW and then only for early dual charger equipped Model S and X Teslas. For Batchawana Bay in particular travelers wouldn't need a lot of charge to make it north to the SC in Wawa and even less when southbound to get to SSM so lower charge rates would not be overly delaying.
It would be interesting to know if this option has been considered by the Tesla SC team.