[Scott Douglas]

It's still a little bit far off to gauge what the weather will be like. If you catch it between storms you'll be real lucky.
I'd suggest trying to coincide gas stops with driver's changes to save time.
When I went to KC Mo last June I tried to keep half a tank of gas in the car most of the time. Could have stretched it but why risk running out in the middle of nowhere when you don't know the gas stations well along the way. I know there's probably an ap for that, but I don't have a smart phone, and besides, it added to the sense of adventure.
Driving at night will be an adventure out west as deer are around, based on the signage I saw along the roads.
I'd suggest carrying enough snacks to make getting stuck bearable for a while. You just never know and it is still winter out here. In AZ you'll be 'at altitude' too, so be sure to bring your warm clothes.

This is going to be fun to follow.