For your privacy you should be thankful that they do not provide a stable prefix.
Ideally there would be a way to request a new one programmatically, akin to getting a new IPv4 address via DHCP if you change the MAC address.
It is rather sad that the internet that we have, what 50-70 odd years post invention is so stifled with nonsense about addressing schemes and that.
You seem to use the term "static IP" as a talisman. I have zillions (possibly gazillions) of them on IPv6 and roughly a few 100 or 1000 on IPv4 (I own an IT company).
Dynamic DNS is a thing, so is ULA for IPv6 which looks quite like IPv4 RFC1918.
We have the tools but you do have to use them.
Compared to a PPP session with an ISP, dynamic DNS is a walk in the park and you can have multiple ones if it is that important. You could even have a mobile phone SMS an IP out.
DNS is seriously resilient to outages. Yes CF, Goog n co have all had outages but the beauty of DNS (and a pain at times if mismanaged) is TTL. Don't set all your records with a TTL of 300. I run quite a few DNS servers - Windows, BIND, PowerDNS and others, not to mention rather a lot of unbound and dnsmasq resolver/forwarder thingies.
Evaluate your requirements, evaluate the resiliency and functionality of the available technologies, evaluate your own skills and take appropriate action ... for you. That works at home just as well as at work.
You may find that you are running your own DNS server (or three) ...