Yes you get a double dip with Miles+Points both ways

Hotel: you get Accor points for the stay and FB miles

flight: you get your miles for your flight and ALL points

The thing is, does it really extend the life of your Accor points? My last stay was on 19th June 2022 and there is no mention of upcoming points expiry on my account. But I don't trust their IT.

Thanks to the Miles + Points yes

if you don’t see expiration dates on the website, try the app, it is normally displayed on the balance once you click on it you get to a page where it says if you have an amount of money to be used and the expiration date

So just to follow-up with the shopping portal: Points finally posted last week, after 7 weeks! The posted date for the points was the day it posted, not when the shopping transaction took place. So if you want to use the shopping portal to extend your points expiration, plan ahead!

Want to add my experience trying to keep my points from expiring. Realized that my points were expiring in less than a week. Signed up for Club Opinions using my Accor member number and completed a survey. Have Silver status, so I qualified for a 600 point bonus upon completing my first survey. Completed a 50 point survey and my Club Opinions account showed that they were crediting me 50 Points for the survey and 600 Bonus Points.

The points credited to my Accor ALL account within 1 business day and my points expiration has now been extended by a year.

The FAQ for Club Opinions says:
So 1 business day is a great result, but probably not a figure to be relied upon.

If you do surveys via e-Rewards (sometimes Accor has a sign up link for specific countries) my experience is that once you redeem a few times, Accor redemptions typically post you your Accor account within 24-36 hours. I think e-Rewards dos a daily batch processing for that unlike IHG redemptions from there, which typically post to my IHG account in 2-3 minutes.

Note that e-Rewards and Club Opinions share a parent company-Dynata.

My recent experience with e-rewards is they now required government - issued ID when redeeming/transferring points. It takes you to "veriff" to get yourself verified. Be cautious!

Just book a table for a fine dining for 2 or 4 persons at some restaurant of Accor hotels network.

That Club opinion worked great. Made 2 surveys and got the points within 2 days. Now my points were extended.

So I had like 8k pts expiring a few days from now. I tried to do the surveys (both Club Opinions and e-Rewards) and spent literally an hour trying to get targeted for a survey, taking these pre-surveys to each survey asking all these questions about me to see if I fit the profile of who they want their survey takers to be. Well I didn't qualify for ANY surveys after about an hour of taking these "pre-surveys", so I gave up. I then saw somewhere in the Accor T&Cs or FAQs that said starting end of 2023, point donations to one of Accor's charities would work to extend points. With no other option other than to continue wasting my time on pre-surveys that I would keep failing (despite starting to change my answers to match match what I thought they might want), I gave up and donated the minimum 500 pts to one of their charities, and sure enough within a day or two my points were extended by a year. The survey thing was super frustrating cuz I used that option to extend points a year or two ago and it was super easy, I qualified for the first survey I attempted, got the bonus (600?) pts for first survey, and my points were extended. Anyways, I wouldn't suggest donating $10 (500 pts) if you don't have to, but as a frantic last ditch option, at least it seems to work...........and saved me 7500 pts in the process.

My Accor+ lapsed, back to gold with 59 nights.

If I have a 1-night stay on 31.12 and check-out 01.01, I will be put up to platinum a few days into January once the night is credited?

Thanks in advance

I think your check-out needs to be in 2023, otherwise the stay/nights/points will count in 2024.

Nope, they'll be credited in 2024 - check out day is what counts.

Does cancelling a flexi booking (booked with Accor points) extend the validity of the points when returned back to the account?

No. It doesn't.