Open an account at one of the biggest banks (JPM Chase, Wells Fargo, etc).

You don't need 16 banks when you can bank with a "too big to fail".

Or open at two of the 2big2fail - the chance that both go t-bills up at the same time is very low (and the one that doesn’t go bankrupt can provide the liquidity until the other resolves).

We use a sweep account that does this automatically with us just holding one bank account