That 200k is a reasonable amount to start withdrawing from a 5M portfolio (exactly the 4% rule from the Trinity study [1]), but you’ll want to adjust it for inflation every year. My favorite tool for planning these strategies is TPAW Planner [2], which visualizes the distribution of withdrawals under various market outcomes. It’ll also suggest a portfolio of stocks and bonds that’ll be safer than just T-bills, which have a high risk of not beating inflation.

1: https://www.bogleheads.org/wiki/Safe_withdrawal_rates

2: https://tpawplanner.com/