A good rule of thumb, according to JL Collins "The Simple Path To Wealth" is that when you can live off 4% yield of the wealth you've accumulated, you can move from the "Wealth Accumulation" phase of your life to the "Wealth Preservation" phase of your life.
If you wanted to comfortably retire today, you'd need to be sitting on like 66 btc.
If bitcoin is trading for $1M fiat, then you would need about 2 btc.
and hopefully NGU outpaces your spending.