Unless I'm misunderstanding you, I've seen other people make the same claim, however it doesn't make sense. Why wouldn't FOPA apply if you're traveling TO PA?
Here is how, I, personally, interpret this law for myself:
A person traveling FROM one's home in one state TO one's vacation home in Pennsylvania, and the inverse, would be afforded protection under Title 18 USC §926A and Pennsylvania law.
First, 18 USC §926A:
Notwithstanding any other provision of any law or any rule or regulation of a State or any political subdivision thereof, any person who is not otherwise prohibited by this chapter from transporting, shipping, or receiving a firearm shall be entitled to transport a firearm for any lawful purpose from any place where he may lawfully possess and carry such firearm to any other place where he may lawfully possess and carry such firearm if, during such transportation the firearm is unloaded, and neither the firearm nor any ammunition being transported is readily accessible or is directly accessible from the passenger compartment of such transporting vehicle: Provided, That in the case of a vehicle without a compartment separate from the driver’s compartment the firearm or ammunition shall be contained in a locked container other than the glove compartment or console.
Without a permit, I may lawfully possess and carry my firearm in my home in Virginia. I may also lawfully possess and carry my firearm in my vacation home in Pennsylvania without a permit. Therefore, I may lawfully transport my firearm; unloaded, with the firearm and ammunition locked in a safe in the cab of my truck; from my home in Virginia to my vacation home in Pennsylvania.
Now, Pennsylvania law:
18 Pa.C.S. § 6106: Firearms not to be carried without a license
<snip>
(b) Exceptions.--The provisions of subsection (a) shall not apply to:
<snip>
(8) Any person while carrying a firearm which is not loaded and is in a secure wrapper <snip> from his home to a vacation or recreational home or dwelling or back <snip>.
Pennsylvania law has no requirement that either of the person's destinations (homes or dwellings in this case) must be within the State. I may lawfully transport my firearm in Pennsylvania; unloaded, and in a secure wrapper; while traveling from my home in Virginia to my vacation home in Pennsylvania.
Now, once I reach my vacation or recreational home in Pennsylvania I may not transport my firearm without a valid license, by vehicle, unless I am traveling back to my out-of-state home or meet one of the other explicit exceptions to the law; or, traveling to some other destination that is afforded protection under FOPA.