Thanks all for the good info. Exactly the sort I was looking for, and much appreciated.

Your posts made me realize I'll have to cope with colder temps than I thought. Whereas I thought liner gloves would be OK, I will definitely bring winter gloves now, and have to sleep with overalls more often than I figured. As for the layers, I have them but I guess I'll have to wear more of them more often than I thought.

Concerning riding in the dark, I had actually planned to ride some of the busiest legs at night because I like the calm. Have dynamo-powered lights and good reflective gear. Maybe I could also ride some of the mountain legs at night if the temps go below 10. That would keep me warm. Plus, I'd choose to ride when it's too cold anytime over when it's too hot.

I'll also plan my schedule to be able to wait out storms or ice for a few of days.

Regarding routes into Phoenix, the ST uses the 70 north of 10. Google maps doesn't object to bike riding on the 10 nor on the 8, but I don't know how reliable GM-bike is in AZ. In Montreal it seems pretty good at avoiding non bike-friendly routes.