Az is full of great places to stay with your RV. You will find that hotels and condos will be at there highest price In Jan. This year is especially big with the super bowl, & the FBR open on the same weekend. I can't remember the dates for the Barret Jackson but it has grown into a huge event with many other smaller auctions in town the at the same time. If you bring the TT you should book a place ahead of time as it is also Snowbird season for us especially after Christmas.
http://www.rvparkreviews.com/index.html
check this site out for a very good list of RV resorts and camp grounds. Scottsdale it's self doesn't have any RV parks that I know of but Just west of Fountain Hills at the Fort McDowell casino there is a very nice resort. And just north of Fountian Hills is a very nice county park both are within 20 min of the car auction. In fact I think the Fort hosts the Silver car auctions at the same time. Good luck.