The fact remains that both MIT and Stanford require scores and your score unfortunately is well below the 25th percentile for both. If you are unable to redo SAt before applications are due, take your shot if you want, but I strongly suggest you look at affordable options a little lower down the “rankings” table or focus on more Canadian universities (which in any case are likely to be more affordable).
Which again begs the question of why you are looking at the most expensive university system in the world. (I don’t know what 4 children means but the point stands.) I know it’s not that reliable for internationals, but have you run the NPC on any of the US colleges to get an estimate of what your family might be expected to pay?