For large amounts i would never ever trust a hardware wallet, too many people involved who know you will be using it for bitcoin storage.
Best to buy a really old laptop and install an old pre bitcoin OS you got.
Then transfer blockchain data and signed transactions via USB stick to a 2nd laptop that is online but never used for anything else than bitcoin core client.
I think armory also got a good system, but i did not check that out yet.
The good thing about that method is you can use really secure hard disk encryption to lock everything down.