All threads that I have read in the past interpret the permit as access to the "wilderness area", not to the portal. In fact, no permit is needed to hike up to Lone Pine Lake (or further), so cannot see how that could be enforced.
On a separate note, to achieve your goal, you will have to be making very good time (particularly with a full pack). Less than 6 hours from the portal to the top, in the dark, comes with some risk. Several people have died on this trail, by going off trail without realizing it (usually coming down). The area above Mirror Lake comes to mind as one spot where others have become lost. You did not mention your dates. Will you have a full moon? That would improve you chances of a problem free assent.