Sounds pretty realistic to me, as you are an experienced cyclist/mechanic. Have you ever toured? If not, the standard wisdom is to do a couple of overnighters to check out your gear. Most novice tourers seem to start with too much. Less is better. If you're missing something, buy as needed.
A gps, though unnecessary, for me makes the ride more interesting. If you've got a 'smart' phone, it'll serve that purpose with the right app.
Check out
www.crazyguyonabike.com for a place to journal your ride.