John,
We at The Red Door would greatly appreciate you and your group allowing us the opportunity to be your host. Check out our website and the various cabin options. A couple of the three bedrooms might do the trick or ??. http://www.thereddoorresort.com/About_the_Red_Door_Resort.html
Our beach (right on shore) is rocky. But ten yds. out from shore is all sand from there on out and safely shallow for the kids. We have a nice dock to swim from and a huge water tram for the kids to romp on while in the water.
Please feel free to call the office and ask for more info and throw around some ideas on how we can help plan your Mille Lacs trip.
THANKS!!!