Using a narrow/full reserve bank.

The Fed has gone out of its way several times to ban full reserve and narrow banks from ever getting access to Fed reserves.

No, normal bitcoin. It doesn't take much to be less risky than "you might have all of it frozen at any time by factors wholly outside of your control".

Or Ether. Or DAI. Or USDC if that's your risk appetite (the diversification of the storage of which is abstracted away already, as you will note it has regained its peg before SVB even reopened under FDIC management). Or a lot of other choices that present themselves.