I have 497,000. I did throw in a factory reman at 460k after burning up a valve seat (low fuel pressure + tune) but my transmission is still original. I would still have zero hesitation doing a cross-country trip.
My only tows have been 1) broken motor mount (motor flopped over far enough to break away the exhaust y-pipe from manifold collector and 2) sheared pinion gear (now I have a bigger rear axle).
FWIW - I bought my van from Enterprise with 105,000 miles. It came with an extended warranty until 150k but never needed to use it.