What is the maximum range of a Blended Winglet™ fitted Boeing 757-200?

Well mate so long as they don't hold it flat all the way & use max boost, and have changed the spark plugs & air filters recently & made sure the brakes aren't sticking, then I'd say she'd go till the fuel runs out commensurate with payload, prevailing winds, airspeed, pilot competence, and air density during the flight.