Hi, CullenFeagin
Welcome to Microsoft Community.
I understand that you are having trouble on need to change your PIN, but currently the computer does not have access to the internet and you have tried very many things. Your solution ideas and mind are great and I understand how you feel.
I'll give you some other options to hopefully solve your problem.
1、Please try to open the mobile phone hotspot, through your device to connect, to see can make the computer into the network state.
2、As stated in the description of your problem, you can try to enable the computer to access the internet and change the PIN by adapting the USB port to Ethernet.
Please note: Please wait for a few moments before recognizing the network, sometimes the network icon may not change but you will still connect to the network successfully.
3、Please try to restart your computer and enter BIOS to disabled TPM.
The steps are:
(1) Reboot your computer
(2) Repeatedly press the Del key (Delete) on the keyboard while the computer is booting up.
(3) Find the Security option in the BIOS setup screen.
(4) Find TPM Configuration and click on it.
(5) Find TPM Device or similar option and set it to Disabled.
(6) Save and exit the BIOS
(7) Reboot your computer.
Please note: The steps may vary depending on the version of the motherboard, you can find the matching steps on the official website of the motherboard brand.
Disclaimer: Microsoft provides no assurances and/or warranties, implied or otherwise, and is not responsible for the information you receive from the third-party linked sites or any support related to technology. If you are going to modify BIOS Settings, please back up all your personal files first to ensure you do not lose data.
If you disable TPM successfully, you should be prompted to please log in with your password after restarting your computer, so good luck!
I sincerely hope that the above solution will solve your problem.
We look forward to hearing back from you.
Best Regards
Arthur Sheng | Microsoft Community Support Specialist