I'm guessing from your lease expiration, that you started your lease in March of 2015. That's around the same time I bought my Model S (I tend to keep my cars for 10 years+).
In the past, the Model S major updates/features/refreshes have happened in April, July, and October.
October 2014 -- announcement of Autopilot, D models (85D, P85D).
April 2015 -- announcement of the new 70D (with new colors),
July 2015 -- 90kwh battery upgrade available for new 85 orders, availability of the P90D, and Ludicrous available on the P90D.
April 2016 -- Model S refresh, with the bumper change.
August 2016 -- P100D available.
I just remember thinking that only a year had passed, and they had already made a lot of changes, including new battery sizes and a new performance model. I think no matter when you get your new car, it's going to be outdated in some features in 3-6 months. And honestly, I think as long as you're going to continue to lease, the timing doesn't matter too much, because it's not as permanent as ownership.
I don't think Tesla will have many P85D Ludicrous CPOs, just because the upgrade was a post-purchase $5k. CPOs primarily come from lease returns and inventory stock. Since the P85D was a hardware-involved upgrade from Insane to Ludicrous, you're far more likely to see this done in a privately owned vehicle, rather than an a lease or inventory model.
I think if the person is leasing, they aren't going to spend very much unfinanced money on the leased vehicle except for maintenance (I wouldn't, but that might just be me). Also, since Tesla wrote in a "We will buy your Tesla at the end of the Tesla for 50% of your purchase price" in their finance contract, that's $5k of their own money that they spent (and that Tesla isn't necessarily covering in the buyout price).
I think you also need to ask yourself, with the new lease, will I be getting a better car, or just getting something about the same?
A P85D has good value -- a look at the current CPOs show them ranging from $71k for one with 41k miles, and $86k for 32k miles. (probably all lease returns, as their VINs are within the late 2014 / early 2015 production).
I've thought about trading-in or selling my P85+DL, but it'd only be worth it if I was getting some features substantially better, and Tesla doesn't make it (yet). (FSD and AP2 are neat and all, but I hardly use AP1 as it is). I'm waiting until I can get a bigger battery pack, and then I can have a P1xx+DL!.
