No Phil, that is not correct. You wrote to go to Advanced Editor of Flat File Source. But you didn't say to go to the Connection Manager for the Flat File Source. Very important distinction for anyone else who may read that.
This was NOT solution:
....from flat file source to destination, using the Advanced Editor to view the data types that SSIS is using as the data passes through the pipeline.
This was solution:
from Flat File Connection Manager, Click Edit, and go to Advanced and evaluate that the size of the property 'OutputColumnWidth' accommodates the size of the input.
Flat File Source and Flat File Connection Manager are two different things:-)