Thanks for the reply. I've done a bunch of Google searching to find the answer before I posted here but couldn't find anything. I too at first put the system image on the data partition of the 2TB drive, and found that the Windows image restoring software simply excluded the whole 2TB drive as a place to where the system image could be restored. It didn't explicitly tell me that restoring a system image would wipe out all partitions on a drive, but that seems to be the implication, or it could be an just odd quirk in the software to not allow a system image restore to the same physical drive as the system image itself is on.
As an aside, I have certainly experienced some odd quirks in Windows software in the effort to try to make a bootable backup copy of Windows on my 2TB drive. For example I thought I could use Windows Easy Transfer, to update my 2TB drive Windows install. Windows Easy Transfer software says in it's description "You can use Windows Easy Transfer to transfer files from a Windows 8, Windows RT or Windows 7 PC to this PC." However, what I found was that the Windows 8.1 version of Windows Easy Transfer has no option to write a migration file. So, I can only read a migration file from the os's listed, but I can't write a migration file so that I can update my backup Windows 8.1 install.
Maybe I could perform an experiment. I could make a small 5-10GB partition on my ssd, copy some data there, create a system image of the ssd on another drive, and then restore that image back to my ssd. If the data partition remains unscathed on the ssd, I should be able to do the same thing on my 2TB drive without losing data. I think that would be fairly safe. I want to have a system image at hand for the purpose of restoring to my ssd anyway, so this would be a test run of an event which requires a system image restore to my ssd. I don't want to keep that small data partition on my ssd after the experiment, but that can be removed later.
That being said, what I should probably do, though, is just cave in and buy another hdd big enough to backup the data on my 2TB drive. Then, there would be no risks of losing data accomplishing my goal of having a bootable, updated, backup copy of Win 8.1 on my 2TB drive. I think that's what I'll have to do, unless anybody has any more applicable information.