I would not volunteer them that information about applying for inland PR unless asked by them. Let them find out for themselves. If you bring it up, then they may start questioning you why you left, knowing full well you broke the rules of Inland Process.
I don't think they would ask you "why you come back with a few months left of work permit?" You are techincally working until November 2013, so you have a right to continue working, however they do have a right to deny you back in. So don't bring it up. Only answer their questions asked and only that. Nothing more.
The reason I say that you can get away from going to US and coming back into Canada is that there are some people that posted that they have been able to enter US and back into Canada a few times with Inland Process in play. The big thing is that they have US visa to enter and work visa to come back into Canada. Canada Border Agents, I believe, tends to be willing to overlook this slight of rule breaking if you have a work permit, between US and Canada and it is a one time thing. Just don't make a habit out of it as your entries are recorded. I believe Sweetsher just came back from Jamaica recently and she has a OWP. If she didn't have a OWP, she may have more difficulty in convincing agent to come back in.
Screech339