File settings for a huge presentation screen

Hi all,

I got a last-second request for a "powerpoint" this weekend from a client preparing a presentation for SXSW. I created the assets in Illustrator, following the size guidelines for PowerPoint. (13.33 inches by 7.5 inches)

However, I've never exported for such a large screen before. I'm afraid my images will look bad, and we don't have time to test. How do I tell Illustrator that while this is a 13" wide doc, I need to look good on a huge screen? Should I change the size of my art boards, or just export it at a high res?

Thanks for any help!