I am in the camp of "driving is enjoyable", and can do 10 - 14 hour days. BUT, I also advocate audiobooks. Makes the drive much more enjoyable.
DW also likes to listen to the books. Used to get them on tape, then CD, now I download from the library as MP3 files. Much more convenient.
My point is, if you have a book, it keeps you more alert. Being more alert makes the trip safer. Looking at scenery is fine, but it takes a long time for it to change, sometimes.
Don't look at the trip with trepidation. Anticipate all the new places you will see, get enough audiobook files to last the entire trip (a couple of MP3 players can hold many hours of files). Drive as much as you are comfortable with. Only you can make that decision. You may fall into the camp of 250 miles a day, but that severely limits your range. If you are in my camp, you make the destination, and have a good attitude. Audiobooks help tremendously.
Enjoy the trip!