I know enough about computers and bitcoin to understand the wild improbability of someone guessing my seed phrase / private key, but in the back of my mind I am always a bit nervous about the random chance that the universe aligns - especially for people using a mass-produced hardware device to generate their keys.

I know that the big companies hold massive amounts in a single wallet and would be catastrophic if someone cracked those - along the same lines, would be catastrophic for me if someone got into my wallet.

Along the same lines, you don't want to have too few satoshis in a single wallet, incase fees are higher in the future, etc.

Mostly curious what you all do / think.