I would have thought that the smaller then centers then the heavier the quilt. I wouldn't be game to try a traditional cathedral window quilt with that size.
BUT
A "mock" cathedral window quilt would be a good alternative. As others have mentioned there are lots of tutorials here. You could also google for "mock cathedral window tutorial". You're bound to find heaps like this one:
http://www.plentifulpennies.com/2009...dow-quilt.html which you could adapt for your size requirements.