30 years ago when visiting the south rim of the GC I decided I had to go down into it. Well, this year myself and Mrs gdi rafted it from the start to the end, all 280 miles of over 8 days. Fantastic trip does not begin to express the experience. Clearly you won't have time for that but one day make time for it. You won't regret it. And I feel sure if you do what you plan you will take up my suggestion. There are considerable restrictions on the numbers overnighting in the Canyon and I had the impression the restrictions were tighter in the winter months, but I wasn't paying a lot of attention to that part of the briefing we received. Sorry to hear you are in LV, awful place but for the micro brewery we discovered called Beirisch (I think).