In contrast to that, I believe that we primarily want to aim for a Kingston-Toronto journey that's actually convenient to use under all conditions! That would include for S60 owners and would also include NOT needing to stay for fully 60 minutes at a SC just to be able to drive at a reasonable highway speed and be able to reach the next SC even in the deep winter cold when our battery range derates down to 65% or less.
Napanee certainly wouldn't fill that bill at all, being only 40 km from Kingston yet still 215 km from Toronto. Belleville is hardly better at 80 km west of Kingston.
Colborne is very close to the midpoint at 130 km west of Kingston & 115 east of Toronto. - Perhaps a very convenient location would be the Big Apple right off the 401.
Cobourg also splits the interval nicely as 150 km & 100 km, while Clarington (at the end of Hwy 115 that leads to Hwy 7 and to Ottawa!) starts pushing the balance the other way at 175 & 75.
IMO Cobourg is a good choice because it uniquely brings the added benefit of allowing drivers bypassing Toronto (e.g. via the 407) to avoid having to visit the really out-of-the-way SC in Toronto: Cobourg to Woodstock is a doable 240 km. In truth, Clarington would perhaps be the BEST choice of all, being 210 from Woodstock and still just 175 from Kingston. In any case, I think that this is a significant benefit and consideration if Tesla really wants to ensure that traveling the 401 corridor will be as convenient as possible throughout, and actually also be competitive to using the ICEV alternative.