I live in northern Colorado (Fort Collins, 60 miles north of Denver). All you need to take care of is the normal services for 100K miles. Plugs are due, and fluid changes would be a good idea before you move.
Aside from that, the car will adjust automatically - you don't need to change a thing.
If you're feeling concerned about the transmission, adding a tranny oil cooler could create peace of mind - but you don't need to do it for the move.
Once you get here, you'll notice the altitude change when you hit the second flight of stairs. If you visit the mountain areas this winter, hydrate and don't try to climb big hills until you've had a few weeks to acclimate.
And we DO sincerely apologize for the lack of humidity. We hope you don't suffer when you're not sticky and wet from head to toe every minute that you're outside. Comfort in the outdoors is one of those minor hardships we cheerfully put up with. Bring hand lotion, the best stuff for dry hands is O'Keeffe's Working Hands. I use the stuff every night before bed.