If the WiFi card is removable then removing it would be the ultimate act of paranoia.
I'm paranoid but why such? Having laptop for cold storage of bitcoins does not require such extremely paranoid measures. There are more dangerous and secret data than private key to 10 000 bitcoins.
The wifi was built into the laptop and there was a bios option to turn it off. Just because I'm paranoid doesn't mean.....
The thinking is that some wifi OS software automatically connects to networks with names like "default" or "linksys" or maybe any open unsecured network. to eliminate that possibility I simply turned it off.