Editing a Design Suite Template File
The source template file you are looking for should be called ds-1col.tpl.php. It is in the mentioned folder.


Copy the file to the templates folder within your theme.
Then rename the file to ds-1col--ds-views-account-wins-page.tpl.php
Make the adjustments you desire.
Flush your caches and you should see the changes.


Read more about views template files here which function really similarly.