There was an good article in Good Old Boat not to long ago about a guy from Maine that that did this very thing. I believe it cost him around 2K to do this. He only putted out of the harbor so he recharged the batteries during the week w/ a small solar panel. I think that any long range "motoring" would be impractical using electric. You'd have no juice left to power up the blender
The generator thing, what's up with that? If you're going to buy a generator to recharge the batteries, might as well just upgrade the motor & call it a day. Even the DC generators cost around 7K.
For reasons that escape me, I always thought sail was the "optimal propulsion system"