I also vote for crazy. We're located a bit south of you in Indiana, and wouldn't consider Yellowstone with our three kids until we had three weeks for the adventure. As an alternative, you might consider a loop through the Colorado rockies. That section of the mountains is much closer and can be reached in two 10 (or so) hour days. We did that part of the country several times over the years with the kids with our favored loop starting in the mountains above Colorado Springs for the first week, then traveling up to RMNP for the second week, heading back on I-80. Kids (and us) loved it.
