Spit- balling here, BUT-
Typical DOW of around 180 tonnes.
550 pax = about 55 tonnes, so ZFW of 235T
MTOW of 350T, so 115T of fuel.
@ 8t per hour, 14hrs to dry tanks, so about 12.5 hrs with reserves, so a zero wind range of around 5000NM at a tas of 480.