If having a hardware wallet which is completely isolated from the internet is your goal, then this is achievable with either a Ledger or a Trezor device if you also have an old computer lying around that you no longer use. You can strip the relevant hardware from that old computer (WiFi card, ethernet port, etc.) so that it will remain permanently offline. You can then use a wallet such as Electrum to create a cold wallet on that permanent airgapped computer which is linked to your hardware wallet, and export the master public key to create a complementary "watch only" wallet on a computer with an internet connection. You would create an unsigned transaction on the watch only wallet, transfer it via USB drive/SD card/QR code to the airgapped computer, plug in your hardware wallet to sign it, transfer the now signed transaction back to the watch only wallet, and broadcast it.

It is a bit more time consuming to set up and use, but it saves you from having to buy another hardware wallet. Having said all that, I'm not sure it adds very much to your set up - as above, there have been no documented cases of successful remote attacks on either Ledger or Trezor devices, outside of user error.