the record for walking across US is 60 days

but that's assuming supplies are provided in an accompanying vehicle. Still, 6 mos sufficed for many to walk alongside Conestoga wagons, pulled by slow old oxen, from the MI river to the West Coast. Anyone with the right gear should be able to just walk out of any country,or area in the world, where there's trouble. There's ALWAYS a fishing village along ANY seacoast, within 1-2 week's hike, and they ALWAYS have sea going vessels, and you can always use gold coins to get a lift, at least to the NEXT fishing village along the coast. Given a silenced .22 pistol and a powerful centerfire pistol, a man who's SERIOUS about getting out of ANY country can do so. It's just a question of how he goes about it, and how many dead bodies he has to leave behind.