I had a high level pokemon run away from me when I tried to catch it. Is it possible to re-encounter it in the same place?
If so, how long do I have to wait until I’m able to find it again?
No, if a Pokémon escapes you can’t find that Pokémon ever again with your account. You may, however, find another one of the same species, but there is no telling about time and location.
However, if you escape from the “fight” you will see the Pokémon again right where you found it (unless the spawn timer has expired).