Stamp duty and escalating prices is why we jumped right up to the house vs adding more intermediate steps - it makes no sense in that environment to wipe out 40-60k+ each jump in lost money
Would agree with a PP that small DC make you tired and you may plateau at work for a bit - that was also my experience - but since then my trajectory has been fine, and salary has increased to make it mortgage and childcare less but I would say we bought with 60% LTV, so not quite at the 800+ range
We did wipe out our savings doing a house renovation, if that isn’t on the cards you’ll be in a much better place
You could also if in trouble do a reverse rent - either pick somewhere smaller in London or rent out the London house and rent outside of London etc there are more options than just selling up