This solution came from Eric Pennington:
- Export your query results to CSV (not Excel)
- Open a blank Excel workbook
- Go to the Data tab and select Get data from Text/CSV
- Navigate to your CSV file and click Import
- You will see a configuration window that displays your data. Set the File Origin dropdown to 65001 Unicode UTF(8).
- Click Load. You should see your data displaying correctly with diacritics