We did this last December with our two DS's -- 8 & 2 at the time. We bought tickets for a Tuesday evening (12/17). The park was open until midnight, but then they had a closing show which lasted probably another 20-25 minutes.
By far, my favorite part was for my DS2 to have the opprotunity to ride Dumbo continuously. We never had to exit as there was no line waiting or just a couple of people towards the end of the evening. My DS thought that his little arm made Dumbo fly. It was probably a once in a lifetime experience.
We enjoyed it so much that on a whim, we bought tickets for the evening of 12/19 (Thursday). Crowds were much heavier and there was a longer wait for everything. The Jungle Cruise was not listed as one of the open attractions and we enjoyed riding that a couple of times in a row. In fact, my DS2 chose this as his final ride of the evening.
We will definately do this again probably on a Tuesday night in the hopes that crowds will be lighter. Well worth the money we spent. HGood luck on e-bay and have fun!