Colorado Springs is the closest airport, at two and a half hours away (115 miles). Denver's airport is only slightly further away at 2 hours and 50 minutes (158 miles).
Yes, you'll probably want to rent a car or coordinate carpooling given the remote location of the house.
Nathrop is the closest town with Airbnb options. Though, we would also recommend looking in the Buena Vista area which is 20 minute drive away.
We would advise checking out Mount Princeton Hot Springs Resort (a 6 minute drive) or the Surf Hotel (25 minutes away). Check out our travel page for specific hotel and B&B recommendations. Though we've never stayed at these places, we are recommending them because of their reviews and proximity to the ceremony.
We definitely recommend clothes that keep you snuggly. The highs are usually in the mid 60's and the lows in the 30's. Otherwise, the weather tends to be dry. If you plan to get high (in altitude) you might want to pack the sunscreen. Your body might be covered but your face could need the SPF coverage.
We ask you dress to keep comfortable for the weather, as it will be chilly. As for the day of, come looking clean, crisp, and classy.
Weird question, but a good one! There are hot springs near at the Mount Princeton Hot Springs resort that you might want to be prepared to check out.