The plant is not dead. You cut evry other leaf off in each row now. When the temperatures stay in the 70's everyday you cut them all off. Cut them off close to the bulb of the plant. Fertilze with a palm fertilizer or a 10-10-10 fertilzer. You cut them this way to prevent the plant from going into shock. When cutting be careful not to get the tough needle like parts into your skin.They are worse than thorns from a rose. Hurts!!! But you should have your sagos looking pretty in about 3-4 weeks with new leaves. I work in a nursery! Good luck with them. I have to do the same.