I made two pies yesterday, one exactly as this recipe, and one "non-dairy" version as I have lactose intolerant family members. In the blind taste test today, no one could say which was "real" - slightly different but both yummy.
For the non-dairy version I used margarine instead of butter; non-dairy creamer instead of heavy cream; powdered non-dairy creamer instead of powdered milk; and added a teaspoon of corn starch disolved in a small amount of water.
I used the same crust for both using margarine instead of butter as a shortcut
I also did a shortcut and baked both at same time, which didnt seem to be a problem. 15 mins at 350 and about 20-25 mins at 325, after an overnight in fridge both set up just fine.