Ah, Wally - you CAN actually hold as long as you like, regardless of fuel!
Boyd Munro did it in the late 80's in his Colemill Panther when the dispute was on. He'd planned to YSSY (not YSBK), ATC said Forgetaboutit, he said no I'll hold, they said fine, he held for a few hours, ran low on juice, dashed down to Goulbourn or somewhere for a top up, back up to the Bindook pattern for a few more hours worth. Can't recall where he went in the end, other than straight to the media to complain how he'd been held for literally hours
