That's fine. You could work 400 miles away, but you would have to buy gas --- Government Motors gives the maximum distance on a single tank of gas and full charge as 300 miles.
The Volt is a gas/electric hybrid. The difference in this and the Prius is that the Volt is a serial hybrid; in the Volt, the gas engine only charges the batteries. (Yes, I know that Government Motors doesn't call it a hybrid but rather a "Range-Extended Electric" vehicle, and technically that's more correct since the gas engine doesn't directly provide any propulsion.)
So I’m not buying anything from Government Motors... So if I want to buy an Hybrid, I would go with a Toyota... The Volt is going to fail and fail big time..