Were the roots brown or white? White roots are healthy. If still white, it might still be alive. And I water my cycads daily when they're outside in the summer. I have 7, and 6 have flushed this year. Only hold back water in cold weather and when they're indoors.

If the trunk is still firm, and the roots are still firm, then it is most likely still alive. I have heard stories of (and seen) where sago palms will sometimes take up to 1-2 years to recover from defoliation and put up a new flush of growth. They are rather shockingly resiliant. If the roots are dark brown and mushy, or anything about it is mushy, then it is likely rotting, and thus likely dead or on its way to being dead.

The watering advice above is good as well. Colder temps, and / or wintering in doors you should give them much less water. In summer when mine are outdoors I give them plenty of water. Fast draining is still important in summer, and I do NOT let them sit in standing water, but I do water them plenty in summer.