I don't know how much I say will translate to warmer zones, few people up here in Minnesota even try to grow bamboo. but this is what I have found after working with F. rufa for ten plus years.
Anything less than a five culm clump isn't worth attempting to transplant. As a general rule, clumping bamboos protest transplanting, anyway. Here, where it is very cold, foliage dies back to the snowline with culms badly compromised. No snow that stays through the winter means they eventually die back to the ground. BUT, if I cut back to the ground everything that seems dead, I most likely kill the whole plant. If I leave it alone, it will grow back with new culms. I've learned not to cut any of the dead stuff down until new culms are at least a foot high and with some leaves.
Hope yours makes it; I dunno.