However, there is a couple with an ER blog (they probably have more than $1m, I don't know) and their plan for healthcare for their kid is to get free healthcare from Taiwan (the mother's home). Which is fine, except they live in the US and are a 15 hour flight from Taiwan. Would you fly a severely sick kid across the pacific? Or, what if you had an emergency where US care is required and then you are on the hook for $$$$ out of pocket. That plan is either unrealistic or just plain irresponsible.
Actually both their blog and the article that drew so many people to it (and into discussing their lifestyle choices) make it pretty clear that they have already moved to Taiwan (initially for much cheaper IVF treatments -- see Making a Baby - Go Curry Cracker!Go Curry Cracker!), and have subsequently stayed on to have the baby. They plan to continue travelling once the baby is about 6 months old.
Good international medical insurance can be relatively inexpensive if you exclude the US as a place for treatment, which they could do because if they needed serious medical care they could always return to Taiwan (which has one of the best medical/insurance systems in the world -- read TR Reid's book on national health insurance systems and be prepared to cry if you are from the US....). You can also buy international policies that cover short-term treatment in the US for a decent price.