I don't know actually I don't think he knew or cared, I don't think he ever intended to survive actually. Being in love with Lily was his big dark secret. I don't actually think he would show anyone his memories once Voldemort was killed. To clear his name as a Death Eater would mean he'd have to show it to the entire magical world. If there's one thing I know about Snape is that he's proud and would despise pity which is exactly what he'd get if he did survive. Can you see him being happy knowing that everyone knew his deep, dark secret? I think he would turn even more bitter and hateful.
I always kind of thought he felt that his purpose was to do everything he could for Harry and he didn't plan to survive it. It's the tragedy of his life I think. What else is there after Voldemort is defeated?
Talk about tragic :'(

The right place for him to be: The Headmaster's office at Hogwarts!!!(being the Headmaster of course)

In hogwarts, doing what he likes best- scaring the kids :)

I think that he would have probably left Hogwarts. He dosn't seem like he would want to keep teaching the kids. He might have opend an apothicary or marketed his own potions. He also most likely would have gotten a woman, someone who could make his horrible past bareable. My guess would be Hermione because she is so smart and could keep up with him. I don't think most women would work for him. I think he could have been happy if he just survived...

If Snape had lived, it would have meant that Harry might never have known his secret, that he was in love with Lily. Think back to the end of Book 7 - Snape and Voldemort in the Shrieking Shack. Snape was desperate to leave and find Harry, because as we know from Snape's memories, Dumbledore told him to go and tell Harry what he needed to do as soon as Voldemort started protecting his snake, Nagini. So if Voldemort had indeed let Snape go, he would have gone and found Harry and explained what Dumbledore had told him, that he needed to die to kill Voldemort.
The only reason Harry found out about Lily is because Snape was dying, and I believe that in his last moments he was desperate for Harry to understand everything - why he had always hated Harry, what his problems with James had truly stemmed from, and why he killed Dumbledore. So he released all of his memories in a last attempt to make Lily's son forgive him. If Snape had just walked up to Harry and told him, I think he would have explained about his constant devotion to Dumbledore, why he killed him, and the information that Dumbledore expected Snape to pass on, and nothing else. No Snape except a dying Snape would have revealed his deepest, probably most shameful secret to Harry.
Incidentally, one of the most touching moments in the book was, during Snape's last few seconds, when he pulled Harry down and told him to "look at (him)", obviously so he could get one last look into the eyes that were identical to Lily's, who he had loved for so long.
Overall, I believe Snape would have gone abroad somewhere - but I agree with the idea that he probably didn't expect to survive. But if he had, I don't think he would have wanted to stick around, he would have settled somewhere new and different, away from his memories of Lily.
(lol sorry for such a long answer btw, i got carried away)

Sorry to break the serious discussion here, but I'm not in a very serious mood at this moment in time so...

Severus would be living at my house hidden in my wardrobe and teaching me how to make potions to give me a better life and get revenge on people who have annoyed me XD
oh and he would be making me lots of cups of coffee since I'm usually too lazy to make them myself ^_^ Yup he'd be my own person slave (in more ways than you would imagine XD)

Again, I'm very sorry for not being serious...

teaching at hogwarts probably vice principle,

Just to be in a lighter mood (or darker, depends on how we may see this) :

"As the Dark Lord is dead once and for all, and the Death Eater gang is no longer hanging around, at last I can have the job of teacher of DEFENSE AGAINST THE DARK ARTS !!!" Severus thought while filing his application for the position for the umpteenth time.

And this time, he would have it on a permanent basis as he's truly the best expert ever in this regard.