I did the same 3 day thing last October (stayed in the Boonville casino though). Make sure you take cold weather and rain gear. I've ridden the trail twice and have had terrible luck getting water at the trailheads. I'm not even sure if they'd have the water turned on at this time of the year. Make sure you're carrying enough calories to keep going. After Boonville the towns are very small and the few eating establishments there are all seem to have weird hours.

This is the best resource I've found:

http://bikekatytrail.com/default.asp