It’s cold, the body would keep for a few days.
It may well be something else based upon the following:
http://www.cnn.com/2015/02/25/us/georgia-execution-kelly-renee-gissendaner/index.html
snip
the Georgia Department of Corrections announced it had postponed the execution
until Monday “due to weather and associated scheduling issues,” department
spokeswoman Gwendolyn Hogan said in an email.
******
Scheduling issues is more likely the reason for delay. What that
entails I have no idea.