Method:
Transaction is created using the UTXO inputs and the output I want. This transaction is then saved to a USB and transported to the offline computer which has the Nano S plugged in.
I have been unable to get unsigned transactions to be signed by Electrum and Nano S on an offline machine (never connected). This seems like something that should be possible? The Nano S is connected (green light on Nano S symbol in Electrum, and Electrum is offline (red circle).
I don't the answer to your question.
however, I was thinking about your method and setup.
It is interesting to do what you are trying to do, but I do not see really a reason to do it (only for curiosity or experimental reasons).
When you plug your usd stick from an online computer to your offline computer, you may be infecting it with malware from the online computer.
Doesn't this defeat the whole purpose of an offline computer?