I also know a Caroline that goes by Caro.
I prefer Cora to Rory for Caroline but it's no more of a stretch that Rory as a nn for Lorelei and after Gilmore Girls that seems easily and readily accepted. If you love it. Go for it. AFter the first few weird looks nobody is really going to question it anymore.
Thanks for the imput! I think I just needed to see that other people thought it would work and it wasn't all in my head!!
Rory and Cora could both definitely work as nicknames for Caroline. I also like Callie. I will say, however, if you truly hate a nickname commonly attached to a particular name, I would look for something else. My mother-in-law chose Nicholas for my husband, but didn't like Nick. She insisted on the full name, and all was well until he started school. He came home after about a week and said he was Nick. He's been nothing but Nick from that day.