I used Sparkmaps to plot my total monthly fitness miles westward. Horrors, between March 26, when I got the idea, and April 26 I only made it as far as Turbeville, SC--I can do better than that! Just pick a neat location within 100 to 150 miles of your home and see if you can walk there in a month.
I can tell that using the same route to California is going to get old real fast. I might try walking north or south, too. I doubt if I can make it to Savannah, but maybe Isle of Palms?