Question

Where does the solar system end?

Answer 1

The first boundary would appear to be the end of the heliosphere which is where the sun's magnetic field ends and the solar wind falls off rapidly. This boundary has been probably crossed by both the Voyager missions. It is well beyond the orbit of Pluto.

The second boundary is probably the outer end of the Oort Cloud which is indeed all of 2 light years away. No human made object has crossed it yet and none probably will in the lifetimes of the youngest present generation. It is the realm of interstellar space.