Вы можете попробовать использовать CASE WHEN
UPDATE #ListingRank
SET Distance = (CASE WHEN Distance < 0 THEN 0 ELSE Distance END),
ActionDays = (CASE WHEN ActionDays < 0 THEN 0 ELSE ActionDays END),
Price = (CASE WHEN Price < 0 THEN 0 ELSE Price END),
Beds = (CASE WHEN Beds < 0 THEN 0 ELSE Beds END),
Baths = (CASE WHEN Baths < 0 THEN 0 ELSE Baths END),
SqFt = (CASE WHEN SqFt < 0 THEN 0 ELSE SqFt END)