It's the powercut scenario I'm a bit worried about, as I'm disabled (invisibly so, but still disabled).
Reading between the lines, I've come to the conclusion FTTP must be available, and it was this PN were trying to push on me.
But yes, I could still renew my current package (inclusive of phone) as of today. They didn't really want me to, though.
I'm sure you can get a portable power station for home
https://www.amazon.co.uk/s?k=portable+power+station+...
With this you can connect your router and electricity will be maintained. I know friends from India and Bangladesh who have regular power failures and they use a power station that immediately feeds in electricity to prevent power cuts.
I've got BT Digital Voice service. When I migrated from TalkTalk FTTC to BT FTTC the phone number was retained. You won't lose your phone number when migrating to Digital Voice. The difference is that your phone number and calling will be through digital voice rather than analogue.
I think, since you have a disability, you may qualify for BT Home Essentials 1/2 which is contract free and costs £15-£20 a month. You can leave at any time. You'll also receive a BT Advanced Digital Home Phone with Alexa Built-In that's wireless and is rechargeable so you aren't dependent on plugging in the traditional phone into your router.
If power failure is a concern and you don't like the idea of connecting a power bank to your router. There's another suggestion. I use rental mobile phone service from RWG sim card for only £2 a month it comes with 750MB data and 100 minutes and 100 texts + free voice mails. Have had this service for 11 months now.
This is way more reliable, in case you need emergency, no more worries about electricity going down or internet connection drop causing phone loss.
If you renew your current contract, it's unlikely that it will be specially cheaper deal compared to a new contract with a different ISP.
The analogue line will ultimately be turned off and even if you don't get FTTP by December 2025 you'll still be forced to migrate to Digital Voice for FTTC. You have no choice.