Fuel pump is the biggest mechanical issue I can think of, that could interrupt a trip. They seem to be more affected by age than by milaege, and 15 years seems like a common time frame for the Ford pump.
The good news is, they usually give some symptoms before they fail. Subtle however. Extended crank time when starting, or the "whine" becomes louder or changes pitch. The other good news is that when it fails, it does it parked. They don't usually just stop when driving. The last good news is you can usually get 1 or 2 more starts by smacking the fuel tank while somebody cranks.
The bad news is you have to drop the tank to change it. If you have a large storage bay in the back, you may be able to add a fuel-pump hatch.
