See if you can rent a portable generator. Most equipment rental places have them to rent. That would be your best bet! Gas powered generator. Call some places nearby and see if they have any to rent.
I want to attend an outdoor-party for 2 days and I need a way to get some electricity. It would need to power a laptop & a led-light. Maybe also recharge of cellphone. What would be the smartest & cheapest way to go about it?