Yes there is decent hatch space. The Premier comes standard with a panel that sits level with the rear seats when they are folded down. Below that is a space nearly a foot high, and below that, there is a foam storage unit that can hold the 120v charger, and the tow loop, and a few other things. This bottom area is where the spare would be. If you take out the panel and the foam container, you get quite a bit of space.
Pictures from:
http://insideevs.com/a-closer-look-a...ailed-gallery/
The Volt has much lower seats and a large hump in the middle for the battery, while the floor in the Bolt EV is flat.
I think 300 miles is possible in the Bolt EV - one journalist had ~42 miles left at the end of a ~240 mile drive, that was some highway speeds, and some A/C. It is possible to shift it into neutral, and coast.