If I were you, I’d definitely look into using an open-source device like Trezor or Passport. The way to go is to have a hot wallet (or a few) for your daily stuff and a cold wallet like Trezor for the bigger crypto stash. For hot wallets it depends what you need, but you can check out options like MetaMask, Electrum or Trust Wallet (which is partially open-source).
Trezor was never in the category of cold wallets, and it is not even today - because you still have to connect it online to be able to perform certain actions. It is possible that you got confused, because what we can consider a cold wallet is another device that you mentioned (Foundation Passport).
Also, anyone can make a free cold wallet if they have an old computer that they will make sure does not have the possibility of connecting to the internet, on which they can then install a wallet like Electrum. On such a computer, you can then sign the transaction and transfer it via SD card or USB stick to an online computer and broadcast it.