SQL Server 2016

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

6 rows affected

DECLARE @colsEAST       AS NVARCHAR(MAX);
DECLARE @colsEAST2      AS NVARCHAR(MAX);
DECLARE @pivotCountEAST AS NVARCHAR(MAX);
DECLARE @sqlEAST        AS NVARCHAR(MAX);

SELECT @colsEAST = ISNULL(@colsEAST + ', ', '') + QUOTENAME(Load_Date)
  FROM (SELECT DISTINCT Load_Date 
          FROM ##CE_tmpEast_ALL) AS Load_Date;

SELECT @colsEAST2 = ISNULL(@colsEAST2 + ', ', '') 
                + ' SUM('+QUOTENAME(Load_Date)+')AS '+QUOTENAME(Load_Date)
  FROM (SELECT DISTINCT Load_Date 
          FROM ##CE_tmpEast_ALL) AS Load_Date;

SET @pivotCountEAST = N'SELECT Work_Group, ' + @colsEAST2 +'
                          FROM (SELECT Work_Group, Load_Date, Count 
                                  FROM ##CE_tmpEast_ALL) AS Count
                         PIVOT(SUM(Count) FOR Load_Date IN (' + @colsEAST + ')) AS pvt
                         GROUP BY Work_Group';
                         
SET @sqlEAST = '; WITH MTD_CountPivot AS (
'+@pivotCountEAST+'
), MTD_Pivot_Tables AS (
  SELECT Work_Group, AVG(Count) AS [AVG Count]
    FROM ##CE_tmpEast_ALL
   GROUP BY Work_Group
)
SELECT CASE WHEN GROUPING(mcp.Work_Group) = 0 
            THEN mcp.Work_Group 
            ELSE ''TOTAL'' 
             END AS Work_Group,
       SUM(mpt.[AVG Count]) AS Avg, 
       ' + @colsEAST2+ '
  FROM MTD_CountPivot mcp
  JOIN MTD_Pivot_Tables mpt 
    ON mcp.Work_Group = mpt.Work_Group
 GROUP BY GROUPING SETS ((mcp.Work_Group),())';

EXEC sp_executesql @sqlEAST;

Work_Group	Avg	2020-01-01	2020-01-02	2020-01-03
Blue	5	2	5	8
Green	5	2	5	8
TOTAL	10	4	10	16