Guide dogs are remarkably intelligent and capable. I was following a Facebook feed of a guide dog (presumably written by its owner rather than the dog itself - they aren't that intelligent) that lived on a canal boat with its owner. He is retired now (due to health problems), but they have a good memory and a reasonable understanding of how to solve problems by themselves, and where things are that they have been to before.
Also heard another tale from a blind man who had to negotiate London just after the 7/7 attacks. His route back to Euston was through Tavistock Gardens, which was closed due to the bomb exploding on the bus. Despite being in an unfamiliar city, the dog managed to negotiate its owner on an alternative route back to the station.