[aerohead]

I lost an alternator 1,500-miles from home. It was a weekend. I might have waited days for a part, at $100/day for a motel room.
A casino courtesy bus took me to the local Wal Mart. I bought a battery charger and a spare battery. Charged the original battery overnight.
Left for home in the morning, driving constant loss only during daylight, until the ignition failed at around 500-miles. Swapped batteries and continued on until dusk, then grabbed another motel room. Rinse and repeat.
Made the trip home with no alternator.
So, for me and the T-100, it was about 500-miles on a battery.