Is any hardware or software wallet which is safe to keep large amount of BTC safe and secure?
A hardware wallet will be a good place to keep a large amount of BTC because only you will determine when you want to use the wallet and only you will know where the wallet is hidden.
Right now, the hardware wallet price is not too expensive so you can buy one or two and send your BTC to two wallets and keep the passphrase safety in a place that only you will know.
Or you can use a HardDisk with installed Electrum and unplug any internet connection and do not connect it with another device that you do not know so you can make sure that your computer with the HardDisk is really safe.