Jeff,
I've made trips across the country a few times, both alone and with "a companion". Although none of the trips have been in my 911. My advice to you is to go for it. Do the trip.
Having a companion along is nice, but honestly, I prefer to make the trip by myself. You can really get lost in the beauty of our country. Take a camera with you for those once in a lifetime shots. And, since you'd be taking your 911, take along a laptop so you can connect to Pelican while on the road.
Life is short and sometimes you only get one opportunity at something. This certainly has the makings of a great one. Sounds like you have a great itinerary worked out. Another good thing about doing this trip by yourself is that any shcedule changes only need to be approved by YOU!
Randy