I have a modest company pension I can take from age 60 without losing too much, a frugal lifestyle, and actually enjoy growing my own food - I have the real beginnings of passable French - I've always had French colleagues and have dreamed of living in France since my teens...
When I moved to France I moved (by choice) to an area where there were no other British. When one of my local mayors heard I was moving to the commune he went out and brought himself an English-French dictionary !! I went out with o-level French from 30 years previously. I went out determined that my language limitations would not stop me doing anything and before moving vowed to never say "Do you speak English?" ever. And that helped massively. French language is very important to the French and you can crucify their language and they will love you for trying and as long as you try they will do as much as they can to help. I never once had anybody laugh at my attempts. for example, I was after a 2rd dog, a puppy, so I looked up the word for puppy in the dictionary and went on my search. And I did not glean from the dictionary that the "C" at the start is a silent "C" and that what I was actually saying was not something you would be asking about !! (in the end somebody at the dog agility club I was taking my other dog to quietly corrected my pronunciation ...
So never ever ever say "Do you speak English?" and always try and don't worry is you destroy their language. And never ever let language stop you doing anything.
The fly in the ointment is the danger that the UK will end up outside the EU so I'm guessing that I would have to carry on paying for health insurance even after I reach 66 ? Presumably I would still be eligible for my state pension thereby at least being able to afford healthcare ?
Assuming the UK stays in the EU, it is actually more complex that this. It is 6 years since I returned to the UK and health cover was the main reason I had to return - not that I needed any treatment or had anything wrong, just that I had to be covered by a health system and my circumstances and Sarkozy's changes meant that neither the French system not the UK system would cover me.
(Double check this as things may have changed but) the moment you set foot in France with the intent to emigrate there you are no longer UK resident. Meaning you are liable for French tax, and not covered by the NHS. If you get ill and return to the UK for NHS treatment you will not be covered and the NHS will charge you. To be covered by the NHS you have to be (or intend to be) UK resident. This seems to only apply to 2ndry health care (hospitals) and I found they do check. In theory you have to be or intend to be UK resident. In practice the 1st question they ask is if you have been resident in the UK for more than 6 months. About 9 months after my return to the UK I needed a minor operation and was referred by my GP to hospital and before I could see the specialist I had to fill in a form and somebody had to come and interview me and I had to take in council tax bill, utility bill, drivers license (can't remember what, but paperwork showing my residence).
Before retirement age, when you move to France the French will not pay for your health cover. When you depart you used apply to UK authorities for an S1/E106/E121 form (it's called something else these days) and based on you NI record, it undertakes that the UK will pay the French for your healthcare. It could run for max. 3 years (duration depending on your NI record). After that you need to sort out healthcare. I believe the UK has now given-up doing this so Google searches refering to it are probably out of date. If you are working for a French company your "NI contributions" will include health insurance (though you and many French will also take out "top-up" insurance but that was not a major expense). If you are not working, Sarkozy introduced a scheme whereby the French state would not pay for your healthcare and the UK will not either (beyond the E106 period). You thus need to take out private health insurance, in theory to provide cover to a standard defined by the French government. Once you reach UK retirement age and get your state pension, the UK government will start paying for your health cover in France. However, I gather (though it's a more recent change to you'd need to check) that after 5 years residence in France (under private health insurance cover) you do become eligible to join the French Healthcare system (to get you Carte Vitale)
(That was the issue I had, early retired, managed to fiddle my E106 to go beyond 3 years, but then the new health private insurance system introduced, nobody offered such an insurance policy at that time so I faced having no cover anywhere. I suspect that by not either the system has changed or insurance companies have offerings. Apparently, at the time I was there the new regs only impacted 3000-4000 people (i.e. those not employed and before UK retirement age)).
Things like EHIC (E111) are not relevant as they are for visitors not being resident in France.
I should emphasise, my info is 6 years out of date and things may have changed, but it is something to investigate before you make any decisions (as private health insurance can be important if on a tighter budget - maybe €1500 for somebody 55-59 in good health hospital treatment only, excluding GP visits).
If you need links to sites for more info, let me know and I'll PM you some.
Things probably get a lot lot more complex if the UK leaves the EU - but I can't see the French evicting all those UK citizens who are already resident in France.
(Sorry for my waffle and please, anybody knowing anything different d correct me as I am a bit out of date).