Blue Tilapia would live, but not thrive in that temp. 64 is on the lower end of eating much and spawning would be spotty at best. If there are shallows or areas that reach warmer temps, the tilapia would do much better. Bright, sunny days would warm the tilapia to ecourage feeding, but I doubt you would ever see the full potential of the tilapia's ravenous apetite or spawning capablities.
