Woah.. that exact thing happend to me about 1400km from home.. and 400 km from the closest Porsche dealer!.. and they couldnt have it before 1 week!..
that was a pain.. :P
I had to have it towed to a BMW dealer 250km from where I was and found an alternator from a part store around with a Overnight shipping fee..
Ended up fine.. but you never want these thing to happend far from home.. :P