Operating outside of the specifications listed in the datasheet will affect the lifetime of the display. I do not have information about how much running outside of the specs will degrade the LED lifetime.
You will need to generate the 330mA for the backlight though, so if your question is about having only a 5v supply, that's fine. Just put your current generating resistor between your 5v supply and the backlight anode. That should drop the voltage into range and provide the current for the backlight to work.
