That sounds like the opposite of what OP wants, because that money can very easily come out, without any pain, and without you even being notified that it's bee

That sounds like the opposite of what OP wants, because that money can very easily come out, without any pain, and without you even being notified that it's been moved - unless you're re-implementing your own bank-level security, I guess. For example, let's say you have $100k in savings. I think you would be absolutely bonkers to store that in some secret part of your (flammable! break-in-able!) house. I guess you could put it in a safety deposit box, and if you needed to spend it in a non-cash way, you could walk it directly to the teller and deposit it and make it available? The equivalent of a cold wallet, I suppose.