Wes...that has to do with many factors. Mainly has to do with the plant it's self. I had one that froze to the ground for atleast the first 3 winters I had it, but has gained much cold hardieness sence then. That plant even took awhile to get from the nusery in New Mexico because they all (their seedlings) froze to the roots and had to grow some leaves before the shipped them out.
They are subject to the cold or rot when they are young. How cold? who knows, it could be a dry cold below -20 Cel. or a prolonged wet cold just below freezing like I had last year that killed so much of my plants.
I had one freeze down to the roots last winter but did not freeze down the past 2 winters before. I also have one that came from the same seed and was planted at the same time in a very open spot and has never froze down.

update
yucca elata 27in

Looking good. 😀 One of mine that died back is growing again.

My other big one died after a winter, but has sence grown out 5 new heads and has been hardy sence. 😀

Cool. 8) I hope mine survives this winter.

heres a pic of it now. 😀

That's Awesome. 8)