How much gas is still in the tank? Might just want to fill it up with some fresh gas and just run it around until you can replenish the system with new gas.
Otherwise, do you see any reason you couldn't gravity siphon the gas straight out of the filler tube? Just get enough fresh gas in there for the engine to run. Dump a few bottles of iso-heet in as well to get rid of any water that may be in the old gas.