S.S.
No tips. But I needed to say you are brave and God bless you for even taking this on.
You could sit in the back with him and play, sing, read. I know I might get lambasted for this but you might want to get some baby videos and a portable dvd player for part of the ride. Maybe breaking the ride down into 15-1 hour increments you can figure out a "schedule" of things to do.
Love your sense of adventure,
S.