To me, the obvious question is - 'why do you want to buy a 1Dx for walking around and traveling?'
You've already stated that money is a concern. Unless you already have all the flagship lenses why buy a flagship body?
The main difference between the 1Dx and the 5d3 is crazy fps and metering, and weather sealing.
Unless you work for Sports Illustrated or National Geographic, the 5d3 will be plenty...and the form factor would actually be better for traveling and walking around.
Then you'll have some extra cash for a pocket cam, lenses, and plane tickets.