That sounds like an amazing trip! Traveling from New Brunswick to Ft. Lauderdale and then across the southern U.S. will give you some great experiences.
For weather, late October in the South should be mild, but be prepared for varying conditions as you head west. Arizona can be warm during the day but cool at night, especially in early spring.
Highway 10 is a good choice for your westbound trip, but be aware of possible traffic around major cities. On your return, Highway 40 is also solid, though it can be a bit more scenic and less direct.
Make sure to check for RV-friendly campsites along your route and keep an eye on weather forecasts as you travel. Safe travels!
