The week before last I worked on two maps for two different non-profit organizations focused on wilderness protection: The Wilderness Society and the Washington Wilderness Coalition. TWS needed a thumbnail of a map for a newsletter; WWC needed a giant backdrop map for a display they are putting together with a graphic designer. As it turns out, the TWS map is the smallest map I have ever made (2.5" x 3") and the WWC map is the largest I have ever made (60" x 45").
Here is an image to give you a sense of the difference.
Biggest on left, smallest on right. Click on thumbnail to embiggen.