Cramping after a long day of riding is probably just from your muscles not being conditioned for what you're doing. Electrolytes during exercise can help, but conditioning is also important. If you can't ride before Aspen, then try to do squats to work your legs.
After you ride each day, a cold water soak helps flush out lactic acid. It doesn't feel as good as a hot tub but it's more therapeutic. Think of pro sports teams' locker rooms with the ice bath whirlpool for post-game soaking.
Compression also helps. If you can buy some compression shorts then wear them at night as you sleep. If you can't afford the shorts, then even a couple of simple Ace bandages wrapped snugly around your thighs will help.
Cold Water Immersion - Australian Sports Conditioning
Compression Gear: Fact vs. Fiction