Been there, done that. I don't remember how far I went after the belt broke, but I pulled into an Auto Parts Store in Hope, Arkansas. I got a belt, put it on in front of the store and got out of town as fast as I could. I was afraid that spending too much time in Bill Clinton's birthplace might cause me to get a disease that pennicilin couldn't cure.
I would have to go back and look in my logbook, but if I remember correctly my engine went about another 150K before breaking.
'84 Euro 240D, 516K miles
'88 300E 5 Speed
Over 800,000 miles in