I I had 100 Bitcoins to store I would look into creating a paper wallet for a large amount and keep some on "Trezor" and up to one on or less on a device to spend btc on the go. I would certainly not keep the coins on a desktop wallet with 100+gb data to download on a computer that is always connected to the internet and I would not mess around with wallet.dat files on a dozen usb drives and I would never ever keep them at blockchain.info or some other 3rd party service.