hillndale-

No clue on the temperture question you asked but I'd recommend a back pack and freeze the bottled water so you have cold water all the way down.

For info on the lodge and camping:

Traveler Description: Inhabiting the Havasu Canyon for nearly 1,000 years, the Indian tribe operates a lodge and campground near Havasu Falls.
Familiar with Havasupai Indian Reservation?

Attraction type: Reservation
Activities: Camping
Address: P.O. Box 10 Supai, AZ 86435
Tel: 520-448-2731