Hi all--got a pretty specific question. I'm hoping to get Ortlieb Front-Roller Classic panniers but want to make sure they'll fit my laptop, a 13" (widescreen) Macbook. The laptop is 12.78", slightly 'taller' than the bag, but I understand the panniers roll closed--would the laptop fit with the bag closed partway? Has anyone tried this and can it be done securely?