Yes, there is a SuperCharger at Sudbury.There's supercharging at Sudbury already I thought, so why build at Espanola, which is only 50 km away? SSM is key because it's the pivot point to either Michigan in the south, or further up north. Superchargers at 300 km apart is doable comfortably at the slow 90kph speed along that part of the highway on the CA side, but of course closer would be better too.
Methinks you haven't seen the official Tesla SuperCharger site which has shown these locations for about two years: