Both Payton Pritchard and the collective crowd at the TD Garden forgot that this was a perfect autumn day in New England and treated the fourth quarter of a preseason game like an Eastern Conference Semifinals game in May. Outside the Garden, people were coming home from farmer’s markets with pumpkins for carving. Inside, Pritchard was carving the Sixers second and third string to pieces, lighting the crowd on fire. Porzingis loved it.