With Gravity Forms, how do I make a form entry count as 2 entries based on a boolean?

I'm working on an event registration form with Gravity Forms. The event needs to be limited to X amount of registrants. Gravity Forms gives us this ability under the "Form Settings > Restrictions > Limit Number of Entries" section. As expected, each form filled out counts as 1 entry.

However, this form also has a "Bringing a Guest?" boolean (Yes or No radio buttons). If "Yes" is selected, I would like the form submission to count as 2 entries. How can this be done?

via Chebli Mohamed