Do you use incognito windows for each website you browse and close them before opening a new one? Do you disable cookies completely?
If not, using NAT doesn't add much privacy for "ongoing session".
Also, how many people share your internet connection? If it's a handful, like most household, your one in a handful, pretty small area. If that's a concern to you, you should use a VPN.
And there are other techniques than closing all incognito windows for each site ... Surely you recognize the difference between uniquely identifying a machine from that?
Again, at this point, use VPNs, ephemeral ssh hop VMs on AWS, Vultur, etc...
For day to day usage, I'm fine with a given IP on a /64. If the police came to find who ssh'ed through NAT from my ISP provided ipv4, it wouldn't take them very long to figure out my wife and kids can't even spell ssh!
Not really a solution to the systemic issue of giving facebook a unique id per device for everyone on the planet. I'm also not just talking about my personal setup. A VPN wouldn't be a satisfactory solution to either.
You know Facebook buys your purchase history from Credit Card companies, right? Disable ad blocking when you go to Facebook, you'll find out they know way more about you than explainable by ip address and email tracking (and now we now purchase history).
If you chose to use Facebook and credit cards, you have bigger privacy problems than non-NATed ipv6!
If not, using NAT doesn't add much privacy for "ongoing session".
Also, how many people share your internet connection? If it's a handful, like most household, your one in a handful, pretty small area. If that's a concern to you, you should use a VPN.