If you had a serial plug-in hybrid with a 20+Kwh battery which also supported exporting 120vac, that would work. AFAIK such a vehicle doesn't exist in North America yet and might not exist anywhere globally.

You start stacking energy efficiency losses (engine -> charger -> battery -> inverter -> charger -> battery -> motor) and economic losses (expensive serial hybrid, higher than expected vehicle battery cycles, still need a large number of tool batteries which wear out in about a year, etc.) though.