Yes, I agree, incremental charges, focussed where the cars spend most inactive hours = parked at work or home.
That means Tesla needs to make a unit with only 100 miles range, at far lower weight and cost, to serve that market. In fact they can sell 100, or 200 or 300 or 400 mile options, also with power options - few need 0-60 at 3 seconds.
So the model 3 could have 4 range options, and 3-4 power options = all in the same chassis to suite the buyers needs.
Chevy is going to do this, so should Tesla once they get enough mega factories - which chevy already has.
I feel the market will proliferate in this manner. Could be overlaid on other models, mini-vans, cube vans, roadsters etc.