Combine flour and salt in a large bowl, cut in cold butter until coarse crumbs form. Gradually add ice water, mixing until a dough forms, then refrigerate for at least 30 minutes.

Roll out the dough into a 12-inch circle, transfer to a pie plate, and trim excess dough. Freeze for 15 minutes.

Cook cranberries, water, sugar, lemon juice, and orange zest over medium heat until thickened, about 10-15 minutes, then cool.

Whisk eggs, sugar, vanilla, flour, and nutmeg until smooth. Scald cream and whisk into the egg mixture to temper.

Preheat oven to 350°F. Spoon cranberry filling into the crust, pour custard over, and bake for 45-55 minutes until set.

Let the pie cool completely on a wire rack for at least two hours before slicing.