kohldad nailed it. Good advice.
The interesting and unfortunate thing about the west is that so much of it is a high elevations. Sure, Tucson, Yuma, and Phoenix are nice, but head up to Flagstaff, Santa Fe, or Moab and freeze your pipes off. Been there, done that.
The advice to follow the coast south then cut across Texas is spot on. We have a nearly identical problem. The DW wants to go south this winter WITHOUT going down I5 toward LA or San Diego.
We are probably taking a more direct route Seattle to Boise to SLC to ABQ?? Hah, our winter snowbird trip will probably be in April. Hopefully Phoenix won't be 100 degrees...
Go south then west and you will be fine.
