Maybe you could somehow combine the Miami-Key Largo and the "Hog's Breath" (or whatever) 100.
The Miami-Key Largo is Saturday, April 18th, 40 miles from Miami to Key Largo. Enter that race and finish it at Key Largo but make that ALSO be the first day of the "Hog's Breath" 100. The second day, Sunday, April 19th, the people who want to complete the "100" would start either at Gilbert's or the Caribbean Club and race down the inside (reverse Steeplechase) to the Channel 5 Bridge and back up the outside to the Islander for the finish of the "100." That would make the two-day event about 100 miles.

I don't know whether this plan sounds viable, but seems like it might attract more cats to both the Miami-Key Largo and the "100."

What do you think? Sounds like a really good course. And chances for trophies in TWO races!