Most definitely! Especially once you get out into the Outlands, that's where most of it is. It's sort of a slow-build from outside the City parameters and then becomes jungle-levels of overgrowth in certain areas, though there are still roads that are at best.. somewhat accessible. Other areas are just your basic kind of field of grasses that are higher than your head!

It would take maybe two-ish days of walking to reach the worst of it? But only about a half day to get to the beginnings of where urban sprawl ends and nature begins!