Help!

I am based in Los Angeles (that's reason enough to beg for help...).

I am in the process of planning a trip with my Harley Deuce beginning December 19th through January 5th (that's a bit over two weeks).

My plan calls for shipping my bike out to either Houston or New Orleans and then drving it back through the Southwest. At first I thought I would stop by the national parks on my way back home (Grand Canyon, Bryce, Zion, Mesa Verde) but everytime I look up one of the parks they mention snow and/or ice during the winter months.

Can someone please help me out and give me some advice and or direction??

Please don't mention Mexico (it's killing me) -- my girlfriend's visa is running short and we're not sure if the renewal will be back in time for our trip so we have to plan as if it won't be and if it comes through then Baja will enter into the picture...

We are both young and in shape - so hiking - rafting - 4x4 rental etc are all good thoughts...

Looking at the map I was thinking initially of hitting Austin - San Antonio - Santa Fe and Vegas -- but am open to any and all ideas...

Any advice and/or suggestions as to roads, side trips, hotels, restaurants - etc - would be greatly appreciated.

Thanks

Michael