So, here is what I did.
1 stick of butter
1 - 8 oz block of cream cheese
1/2 cup sugar
1 cup splenda
1/2 cup key lime juice
1 graham cracker crust
In stand mixer bowl, whip together softened cream cheese and butter. Dribble in the lime juice, whip well for a few minutes, scraping down the sides a couple of times. Add sugar and splenda and continue beating for about 3 minutes until blended. Add eggs one at a time, mixing for about 4 minutes in between.
Now, at this point this did NOT look like PW's chocolate filling. It was way too jiggly and loose, so I decided to cook it. I poured it into the crust until quite full, then put it in a 350 oven for what I intended to be maybe 10 minutes. Twenty minutes later when I took it out ( I forgot it while I was folding clothes) , it was a nice goldy color and really puffy. It fell a lot as it cooled, but was still sticky in the middle. I expected it would be a dismal failure ( right in line with my jello cookies), but I stuck it in the fridge anyway.
Today when I was on the way home I thought about it and decided that if my glucose was less than 85 I would try a little piece. It was 77, so I cut myself a little wedge of the pie and enjoyed the heck out of it. The texture was a lot like cheesecake, but not nearly so rich.
I don't know if using all splenda and no sugar would make it come out the same, but I bet you could reduce the carbs even more by making the crust out of sugar free vanilla wafers, or just lay the cookies in the bottom of a pie plate, then rim the pan with them after pouring the filling in. That would eliminate whatever sugar and fat might be in the crust.
Anyway, one of y'all needs to try it and see if the results are repeatable. The true test will come when I get a kid or Big Daddy to try it. I won't tell them it is "low sugar" so as not to slant their opinion.
I bet it would be really good with some pumpkin!!!!!