1) Doug is 100%, as are ibcs and adiggs.
2) Not sure you want to run the house on the battery in the roadster, because if you run her too close to dry you will be SOL.
3) That brings us back to 1... Go for a drive? (and maybe buy a generator).
I lived for weeks without power here in NYC after Superstorm Sandy. I feel your pain.
Best,
T