To be honest I really think that the car that could really make a dent in gasoline use could be the Chevy Volt. It will be much more affordable for a lower income family than the Model III, has no range anxiety, and since 80% of driving is commuting or local driving it would vastly decrease use of gasoline if it were sold in large numbers. We have both a Model S and a new Volt so have actual experience with both.
The logical progression of ev buyers looks to me like this:
1) high end buyers ... Models S and X
2) the buyers able to afford $50 to $60,000 ... the Model III (still really rich for most people)
3) the affordable car that will run most days on electric but be suitable in a single car family as well for long range driving, and be affordable for a bigger slice of the population .... Chevy Volt
4) Second cars for strictly city driving provided one has another vehicle for long distance driving .... Leaf, and other low range ev's
This leaves no place for the Bolt, except as a longer range version of number 4. Without fast charging like Teslas, there is really no place for the Bolt, or the BMW i3, etc except as second cars.