Park slope preschool winter start

We are currently trying to move to Park Slope from the suburbs and are curious about the possibility of getting into a preschool mid-year. Our son is 4 and will be in preschool where we are until we move (hoping to sell soon and possibly move in the winter--around February/March). Has anyone else done this? Were you able to secure a preschool spot (I know UPK is unlikely given the high demand, but any idea on private preschools in the area)? I think it will be better for him to be enrolled in school to make the move easier (built-in friends and routine right away). Any places we should reach out to? Advice? Thanks!