The price difference between the S85D and the P85D is really only about $10K because part of what you pay extra for the P you get back when you sell it.
This is what I call stretch rationalization. You know what you want so you stretch really far to find a way to rationalize it. The upgrade cost for 85D to P85D is $19k, $21k if you go from leather to next gen seats with the upgrade. It's not $10k. You have no idea what the resale market is going to be like.
Things that can mess up your idea that you're going to get back half of that premium to upgrade to the P85D:
* P85D probably will go through rear tires faster simply due to the bigger rear motor (you may eat up some of that $10k buying tires you wouldn't have bought).
* P85D has less range than the 85D, they may be desirable to a certain segment but I suspect the 85D will hold value better.
* Options don't seem to hold their value as well as the base car. Even Tesla's calculation for the resale value guarantee only gives 43% of the price you paid to upgrade to the P.
* That only really works if you sell the car sometime before 3 years. Some people don't do that.
* You're not calculating the cost of money for keeping the $10k tied up for however long you are keeping the car. If you figure 5% cost of money that's another $1500 dollars in cost even if you're absolutely right and get back $10k of the $21k to upgrade. That pushes your cost up to at a minimum $13,576.25.
* Tesla comes out with some other new hotness right around when you need to sell (pushing the resale value down due to the market being flooded) in order to realize your limit on the upgrade cost.
There is really no way the P85D is going to be most of the Ds. The availability in December has pushed some people into P cars that wouldn't have otherwise (e.g. people with green and brown 85D orders that moved their order to a P85D in order to preserve their color). The vast majority of the public just simply doesn't care about or want the performance that the P provides. I fall into this camp. I could have bought a P85D, I'm getting an 85D. By all means if you want a P85D get one, but don't presume everyone is the same as you.
The reason there's not much talk about 85D orders right now is simply that there's nothing to talk about. Everyone is sitting in the queue. The only thing to talk about would be that some people have been pushed from February to Late February or Late February to March. Come mid to late January there will probably be people who are talking about what's going on with their 85D orders.