merrymeeting, the biggest factor that determines the impact to you is if you are on the actual route. To Walker's point there are lots of other paths you can choose to get around if you know the area.
In the case of the Lake, if you happen to be driving around the lake on a busy weekend day and a Presidential Motorcade is on the move, you may change your opinion

It's certainly not the end of the world but you can be held up in traffic for a while if you hit the right place at the wrong time.