How to sort specific column when using GROUPING SETS in SQL Server?

If I remember correctly, in SQL Server, it is not recommended to use "ORDER BY" when there's already a GROUP BY GROUPING SETS.

I have two columns: [UPC#] & [Description] both are varchar.

My grouping sets is like this:

GROUP BY 
GROUPING SETS 
(
    ([UPC],[Description])
    ,()     
)

I don't have 'ORDER BY' but it's automatically sorting the Description column.

If I added a 3rd column, sum(Qty), then it doesn't sort by Description anymore. But if I added

ORDER BY [Description]

Is there a way to sort the Description column and still let the grand total of sum(Qty) be at the last row instead?

Thanks.