Yes,
iOS always has in some capacity. If you load directions in maps while you have wifi, page through the directions start to finish. It loads the pages into memory and caches them.
I used my wifi only iPad in iOS6 to simulate a trip to Chicago, shut wifi off, opened quite a few other apps (using memory and such for other things), and was able to return to maps ( with wifi still off ) and still run through all the pages to get me to my Chicago destination.
Test on your device to make sure, however this trick has worked for me since my iPod touch 1st generation. The nice thing with ios6 maps, it appears to load more of the surrounding area into memory than previously.
::edit::
Though I don't know what capacity you are looking for in your offline maps.