I work full time but have a lot of juggling childcare wise
I’m guessing he doesn’t do quite as much juggling as you? In which case he’s already using you to advance his career at a cost to your career and financial security for you and the family as a whole.
I see the temptation to let him earn the money when the disparity seems big, but it’s often a bit of a mirage. As you’ve acknowledged, it can all change in a heart beat (and possibly it’s more likely to change if there is such a power imbalance); it can become a hard rut to get out of If you change your mind and find your skills are too out of date to get you back in at anything like the level you were before; as the children grow the amount of time you spend doing things that seem important over what seems like grunt work tips towards the negative; and then, eventually they leave home and what do you do then? Also, most studies show that people who do not work tend to be less happy than people who do work unless they are independently wealthy (i.e trust fund or other investments) to the extent they don’t have to think about money.
215k sounds like a huge amount of money, but in London it may not go far enough to make a life of leisure that fulfilling, especially if you are intending paying out for private school. Although he’s earning 3x your salary, progressive taxation likely means he’s bring home a bit less than 3x what you currently do so your overall income may be a little less than with your income and him earning double. It wouldn’t be enough to spend without concern. You’re probably a very resourceful woman and I don’t doubt you could easily add thousands worth of value to your home life, but would it be work you’d want to do? And will it be value you’d all appreciate as a family over having the money to spend?
Finally, what would your DH really think about you just giving up work because he’s earning? Would he see that as reasonable? And if so, why? What does he think your role would be?