The Bolt looks good, and is a step in the right direction, but it's a MUCH smaller vehicle.
Although I can't find dimensions for the Model 3, interior volume wise, the Bolt is comparable to a small SUV. With the seats up it has 16.9 cu feet of cargo volume (which is better than a Honda Fit or a BMW i3) and passenger dimensions that are better than my wife's 2005 Toyota RAV4.
With the seats down, it has 56.6 cu feet of cargo volume, which is quite a bit. 56.6 cu/feet is almost as much as the Model S, and, arguably, more usable as the cargo area is one big cube and has a large rear hatch opening.
Smaller on the outside, maybe, but I've had the fortune to sit in a pre-production Bolt and it's nice and roomy. It was airy and felt noticeably bigger than the wife's RAV 4.