The only way I can think to do it is if the map requires you to follow a specific path. Then, you could use just one Quest event, and set them up in stages. That would only require you to reset one Quest variable at the end. But, if there's any alternate paths, it won't work. Though, if you use Quest Stages, you might be able to shorten the number of variables used and use a couple of Quests, depending on the paths. If it's an open area, like a city, it would never work that way, though, as you'd have no control over the direction the player would travel.