When we were there last December (after PCC 2.0) there were bicycle security folks riding around. We were never out as late as you will be, but we never saw anyone who wasn't there as a guest, either. Some of the nightclubs at City Walk will still be open, so there should be people around (they may be hammered, but...)
My point, although poorly made, is that you should be safe. There will be other DISers staying there, maybe you can find a group to walk with?
Have a great time! I wish I could join you!
--H
