Legend has it that Jonathan Boyer won RAAM in 1985 while getting six hours of sleep per night. He won by two hours according to the Ultracycling Hall of Fame site at
http://www.ultracycling.com/about/hof_marino.html.
Anyone have more definitive information on that race and Boyer's schedule? Boyer was an ex-TDF rider, so his cycling superpowers might have allowed him more flexibility.