@Treue I mean, you could do it, sure. Just be prepared to wait around for a long long time, cuz that's a big fuel tank and you need a lot of fuel. Maybe start the siphon in the evening and have someone check on it overnight to make sure it's still going.
@Gunther Make sure that the tank takes standard gasoline. Some of them use diesel fuel, and that's gonna be thougher to find, though plausibly in better supply because it's not as popular.
EDIT: never mind, checked the journal.
They should just be glad they don't have one of those more modern tanks that take jet fuel. That would be a pain in the nonspecific waste secretion area to find.