This doesn't make sense.
Noone can 'hack an address'.
Either someone compromises your computer / mobile / wherever you store your private keys.. then he has access to ALL private keys stored there. Doesn't matter if you have your coins on 1 or multiple addresses.
Or someone gains access to your seed (which you have stored on a piece of paper (e.g. evil maid) / on your computer (very bad practice) / etc..). In this case the attacker also gains access to all of your coins. Regardless how they are split between multiple adresses.
With small amounts on a lot of addresses, you are increasing the size of the transaction. The more inputs are consumed, the bigger the transaction is.
And the bigger it is, the more fees you have to pay.
Bittrex is currently holding ~128.000 BTC in their cold wallet - on 1 address: https://live.blockcypher.com/btc/address/385cR5DM96n1HvBDMzLHPYcw89fZAXULJP/.