I've done this several times, and it definitely works !
The only issue I've found is maintaining scale consistency as the map grows. After a few years, the initial area looks small compared to the whole map, but with a lot going on inside it. But (and maybe it's just my own personal flaw) if I deliberately constrain the initial area by making it in some way completely self-contained (an island, space station, elemental sub-plane or whatever), I soon get frustrated with the inability to introduce new themes and expand the world.