A method for increasing an emissions compliant load level range for a combined-cycle power generation system, said emissions compliant load level range being a range of an operating load level of the combined-cycle system from a maximum operating load level to an emissions compliant load level limit below which the system ceases to be emissions compliant, said combined-cycle system having a gas turbine system which includes inlet guide vanes for directing ambient air into a compressor, from which compressed air passes into a combustor to react with fuel, and deliver exhaust gas to a turbine, where the exhaust gas expands to generate power, and the exhaust gas is sent from an outlet of the turbine to a heat recovery steam generator (HRSG), said method comprising: reducing a supply of fuel to the combustor, while simultaneously reducing a supply of air to the combustor, to maintain an emissions compliant fuel-to-air ratio and an emissions compliant flame temperature determinable based on measurable exhaust gas temperature at the outlet of the turbine, as the operating load is reduced from the maximum operating load level to an intermediate load level; bypassing an air flow from the compressor around the combustor to form a mixture of bypassed air and the exhaust gas sent from an outlet of the turbine prior to entry into the HRSG, as the operating load level is reduced from the intermediate load level to a lower load level within the emissions compliant load level range, said bypassing of the air flow having a cooling effect on the downstream temperature at the HRSG; and increasing an exhaust temperature set point of the turbine to increase the temperature of the exhaust gas at the outlet of the turbine in a coordinated manner with the step of bypassing air flow from the compressor, said exhaust temperature of the turbine being greater than a threshold temperature corresponding to an emissions compliant flame temperature and having a heating effect on the temperature of the mixture of bypassed air and exhaust gas at the HRSG as the operating load is reduced from the intermediate load level to the load level within the emissions compliant load level range, such that combination of the coordinated heating effect and the cooling effect limit the time rate of change of the temperature of the mixture entering the HRSG as the operating load is reduced from the intermediate load level to the load level within the emissions compliant load level range. reducing a supply of fuel to the combustor, while simultaneously reducing a supply of air to the combustor, to maintain an emissions compliant fuel-to-air ratio and an emissions compliant flame temperature determinable based on measurable exhaust gas temperature at the outlet of the turbine, as the operating load is reduced from the maximum operating load level to an intermediate load level; bypassing an air flow from the compressor around the combustor to form a mixture of bypassed air and the exhaust gas sent from an outlet of the turbine prior to entry into the HRSG, as the operating load level is reduced from the intermediate load level to a lower load level within the emissions compliant load level range, said bypassing of the air flow having a cooling effect on the downstream temperature at the HRSG; and increasing an exhaust temperature set point of the turbine to increase the temperature of the exhaust gas at the outlet of the turbine in a coordinated manner with the step of bypassing air flow from the compressor, said exhaust temperature of the turbine being greater than a threshold temperature corresponding to an emissions compliant flame temperature and having a heating effect on the temperature of the mixture of bypassed air and exhaust gas at the HRSG as the operating load is reduced from the intermediate load level to the load level within the emissions compliant load level range, such that combination of the coordinated heating effect and the cooling effect limit the time rate of change of the temperature of the mixture entering the HRSG as the operating load is reduced from the intermediate load level to the load level within the emissions compliant load level range.