The downside to doing this is you have to pay the transaction fee twice, once for the $1 and once for the $499,999. The transaction fee is a fixed amount irregardless of how much is being transferred, so it's definitely better to pay the fee twice than risk losing it all if you are even slightly unsure.
Friendly heads up - this isn't a word, and also happens to be one of those slip-ups that people will judge you extra hard for. Say either "regardless" or "irrespective".
