Lol first of all, I hope the dates in your title are wrong, or else they are already here
I have stayed at the Clarion before. It was perfectly nice, comfy bed, just a little too far away to walk comfortably (about 1.25 miles from the gate). Learned that lesson the hard way

The only bummer is that Clarion charges $12 or $14 (can't remember) for parking, so if they drive to the parks, they'll be paying twice for parking - once at Clarion, once at the park. I can't remember but I think there may be a shuttle they can look into for a small fee.
I went to the parks yesterday for the day with friends and it is pleasantly uncrowded. TSMM was 25 min and Indy and Space were 30, but other than that everything was walk-on.
I'll leave the big touring suggestions to the pros, just wanted to chime in on the Clarion!