The entire benefit of Ceres is that you get access to nuclear power without having to risk radiation exposure for Earth. Cold storage is famously low power usage, the storage drives are powered off. It doesn't take advantage of the entire point of building a datacenter on Ceres. It takes orders of magnitude less energy to fill a SD card full of data on Earth and leave it here than it would to launch it into space in case we need to read from it in the future.

I was trying to be funny in my comment. But thanks for a very informative reply!