I have stock sales > $10 million. TurboTax says, "Cannot exceed $9,999,999.99." Is there a workaround, or do I need to do a manual return?

You can break up the single transaction into two (or more) smaller units. 

Otherwise, the number of digits in data entry field is limited to nine.

Thanks much!  So, since there is only one box on the input for 1099-B, Box 1d on the Borkerage 1099-B, do I need to simply need to create another 1099-B broker entry (with the same name?) for the difference?  Otherwise, where would I enter the overflow for Box 1d?  Thanks!

I would create another 1099-B (containing exactly the same information with respect to the broker, tax ID numbers, account numbers, etc.) with the overflow.