I don't know how old you are, but I do know that if you are on medicare, you have to continue to make the payments IF YOU EVER THINK YOU MIGHT REURN TO THE US. Otherwise if you do come back you will hit with having to pay what you didn't pay while you were done.
We checked into stuff in 2016 and then when Biden was elected we exhaled. Big mistake. We are now in our early 70's and no one wants us. We're old and can't really contribute to the economy. My grandmother was born in Canada but I cannot find her birth certificate anywhere so I have no proof. Checking baptisms not but don't what religion, if any, they belonged to. There is still Portugal which is affordable but again, it's the health care and the monthly payment to Medicare if you think you might return.
I don't want to scare anyone, but it wouldn't surprise me if the current administration would try something like, you can't get your social security if you have relocated overseas. Wouldn't surprise me in the least.
I've got English, Irish, German and Canadian but too long ago (except for the Canadian) to do any good. Just make sure about your medical insurance and if, or when, you decide to draw your SS.
Good luck.