I can't offer any suggestions on what to do with the money if I don't know more information about someone's finances. The advice for managing the $800k Roth IRA and $400k money market account will be different if someone spends $5,000 per month or $20,000 per month. The Redditor is earning $40,000 per year, which comes to roughly $3,333 per month before taxes.
One of the most important decisions anyone has to make in achieving their financial goals is how to invest their money. This might sound like something you can decide in just a few minutes, but let this be a reminder that any decision now can have long-standing consequences, so you have to decide carefully what your first or next move is going to be.