;WITH tt ([ORDER],id,category,people,N,N_Places_Remn,B_With_Adult)
AS
(
	SELECT	t.*,		
			MAX(CASE WHEN t.category = 1 THEN 1 ELSE 0 END ) OVER ( PARTITION BY t.[order],t.N / 7)   B_With_Adult -- признак закрепления за взрослым
	FROM (
			SELECT	t.*,
					COUNT(*) OVER (PARTITION BY  t.[order] ORDER BY t.[order],t.id, t.category DESC , t.people )  N, -- для определения SeatsBlock
					5 - COUNT(CASE WHEN t.category = 0 THEN 1 END ) OVER (PARTITION BY t.id)	N_Places_Remn	 -- остаток свободных мест для детей
			from @T t
	) t
)

SELECT  t.*,
		DENSE_RANK() OVER (ORDER BY ISNULL(t.new_order,t.[order]),t.N_New / 7)	AS 	SeatsBlock
FROM (
		SELECT  t.*,
				COUNT(*) OVER (PARTITION BY  ISNULL(t.new_order,t.[order]) ORDER BY ISNULL(t.new_order,t.[order]),isnull(t.new_id,t.id), t.category DESC , t.people ) N_New
		FROM (
						-- распределение по взрослым
						SELECT  r.[order],r.id,r.category,r.people
								,v.[order] new_order,v.id new_id
						FROM (
								SELECT	tt.*,
										ROW_NUMBER() OVER (ORDER BY (SELECT 1)) N_B_With_Adult
								FROM tt 
								WHERE tt.B_With_Adult = 0
							) R
							INNER JOIN 
							(
								SELECT  rr.[order],
										rr.ID,
										ROW_NUMBER() OVER (ORDER BY (SELECT 1)) N_B_With_Adult
								FROM (
										SELECT	tt.[order],tt.id,tt.N_Places_Remn
										FROM tt 
										WHERE -- заявка либо текущая,либо следующая
											tt.[ORDER] >= 
											(
												SELECT TOP 1 rr.[ORDER] 
												FROM tt  rr
												WHERE rr.B_With_Adult = 0
												ORDER BY rr.[ORDER] 
											)
										  AND 	tt.N_Places_Remn > 0
										 GROUP BY  tt.[order],tt.id,tt.N_Places_Remn
								  ) rr
								  -- разбивка на строки - количество свободных мест для детей
								  CROSS APPLY 
									(
										 SELECT NULL  N
										 FROM 
										 (SELECT 1 N UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5) kk
										 WHERE kk.N <=  rr.N_Places_Remn
									) h
							) V
							 ON r.N_B_With_Adult = v.N_B_With_Adult

						UNION ALL	 
						-- без распределения (as is)
						SELECT	 r.[order],r.id,r.category,r.people,NULL,NULL
						FROM tt  r
						WHERE r.B_With_Adult = 1
		) t
) t