I actually tried to work out a trip just like this once, and discovered there are a lot of different paths you can take, but certain parts of the sequence are heavily constrained. You can also, I believe, start in Pennsylvania and end in the same state that the “official” answer designates, but that’s the only other choice.
And not only is the last state completely determined by the stated restrictions, the last seven states will always be the same, and there is only one order you can take them in.