If you are asking for other people's opinions on what they would do.
Personally I would just keep it going and not reset my stats. I had to do sort of the same thing in Black Ops ( bring my kd back up ). And I feel like once you come back from down 2600 kills and just keep going up, it would be more satisfying.
Besides you did all the work to get challenges and get to 15'th prestige might as well show it off. At least wait until they release 16-20, who knows by then you may feel like going through another prestige. Like you already said you can always buy a 3 month or whatever..
Think that maybe what I will do. I just wish they would make the prestige system more interesting. I am starting to hate grinding and mindless emblems. I think future prestige systems need to actually prove skill. Something like in order to prestige you have to have x amount of challenges done and every time you prestige you unlock a different gun, perk or killstreak. Plus they can make it interesting by not resetting challenges that way ranking up is not as quick. It only takes me about 20 hours tops of gameplay to go through a prestige and that is only if I do not have any prestige challenges or gun challenges about to hit.