Replying to Cross Country Road Trip PA-CA

So, as the semester comes to an end. I was just accepted for a semester in LA next Spring.
Living on the east coast, I'm super excited to get out west. As well as do this internship.

I need a car out there as well, and I don't want to rent one. So the plan is to drive. From Philly to LA. I want to leave on christmas day, and get there the 4th. Its a 10 day trip I could make it 12 days if I need. But my main goal is to sight see and shred. On the list is: Breck, Park City, Brighton, Copper, & Keystone.
I have a friend in Iowa, so the plan is tackle a 16 hour drive there. Sleep and rest, then do the 11 hours to Colorado. So that leaves me about 7-8ish days in the Colorado and Utah area.

So my question is, besides riding at the mountains above, what would you want to see along the trip or should i possibly make another stop somewhere else. Grand Canyon and Vegas seem like they may be possible options.

Also if you were in my shoes, would you want to travel alone, I honestly don't mind. Or take your GF who skis as well, not a park killer, but she could totally ski anything confidently. My only concern is that she'll get tired riding that much and ill feel bad riding while she's not or ill have to stop riding. But it would be nice to have someone to drive and ride with and a nice goodbye since I won't see her for 16 weeks while I am out there.

Thoughts?