Where are TextEdit files that are not moved to iCloud Drive stored? After upgrading to Yosemite I did not migrate to iCloud Drive and iCloud text files were in a local folder which was very difficult to locate. 

I can't find these files now. They were in a folder that had a long "com.open" or similar name.
If you haven't migrated to iCloud Documents then they are still stored in the iCloud Documents folder in

~/Library/Mobile Documents/com.apple.textedit/