If the load is low (2 Amp-ish) from a few work lights and maybe a radio. Have you looked at linking a few heavy gauge extension cords together, or making your own? Not the best solution for long term or high amp requirements, but it might get you over this hump.
Or - is there a neighbors house that is closer that would let you plug into them if you slipped them a few bucks?
Of course there is this:
ThinkGeek :: Wireless Extension Cords