A refrigerator appliance with a freezer chamber divided into multiple compartments and features for selectively adjusting the temperature within one of the compartments while maintaining the temperature within the other compartment(s). The refrigerator can include evaporator including a first evaporator section and a second evaporator section, the first evaporator section positioned in a first evaporator chamber and the second evaporator section positioned in a second evaporator chamber. An evaporator shutoff valve is positioned along at least one of the first or second evaporator sections for selectively allowing fluid communication therebetween.