You can retire comfortably almost anywhere with $2M. 3% is an extremely safe "withdrawal rate" if you invest the money in index funds, and that gives you an annual income of $60k. That's a solid middle-class income anywhere in the US, and luxury in South-East Asia.
Apropos of nothing, health care before age 65 in the US (prior to the ACA, and possibly again) peaked at about $36K/year (age 64). That leaves you with $24K of your $60K to live on. Not saying it isn't doable, but it isn't as much as it once was.
All I'm saying is that retirement planning is a bit weird because if you do it when you're 20 you might miss some expenses that older people have that you are not yet aware of :-)
Healthcare in Estonia is provided to you by your employer (which is required by law, so every employer will have to pay the healthcare tax on your behalf) which will include everything you would need from healthcare. Once you reach the age of retirement, healthcare is free. In fact if you don't have a job, and I've been jobless, then it has cost me only 5 euros (a fixed fee at the registration) in a hospital to get fixed up (broken leg, broken toe, infections ..)
I'm more and more convinced that U.S simply hates its people.
Its one of the options that people talk about, in particular moving to Canada. My in-laws moved to Brazil not only for lower health care costs but it was less expensive to hire in home care giving staff.
That makes visits from the grandchildren and family more difficult though. Something that can be important in your later years.
I can tell you that most Europe will fix you up for much lower rates than USA -- heard that from people in the Baltic countries, Netherlands, Belgium, Poland and a few others.
In my country -- Bulgaria -- I recall somebody on the news saying they pulled their US cousin in here and they got a complex multi-phase operational treatments (not good with medical English, sorry!) with 3 months of hospitalization... for a sum of money that would equal 1 week in hospital in USA plus only the first operation (out of 4-6).
Medical tourism is becoming a thing here in Europe.
It's morbid, but why even have insurance at that age? Any major accident or stroke or whatever could be close to the end for you anyway and you still have the 2M if you absolutely need to pay
A trader who made millions of dollars would diversify his assets, especially if he lived during the last 2 decades and thus had access to cheap properties.