There are various ways to compress it to fit, and reducing the quality by increasing compression is the most common. However, if you have a slide show, the compression shoud be very good, and you may very well find that a VBR export will be a lot smaller than you think, with no reduction in quality. Just allow a very low to a medium high data rate, and the very low will be used when nothing moves.
If you did a lot of Ken Burns movement, then it will still require a large file size. But remember, no movement is extremely easy to compress.
Steven
Adobe Premiere Pro 1.5 / After Effects 6.5 Pro https://www.stevengotz.com
Learning Adobe Premiere Pro 1.5 https://www.lynda.com
Contributing Writer, PeachPit Press, Visual QuickPro Guide, Premiere Pro 1.5