I am finding it incredibly frustrating that this is all so difficult to do.
It isn't difficult.
The issue is simply your provider of choice doesn't sell the product you want.
You need to pick another provider or split the landline number and broadband.
Pick your VOIP provider and migrate the number to them. This needs to be your 1st step if you want to retain the landline number.
As you know it ceases your broadband.
Take Ronskis advice and run a 4G SIM for a month to keep you going while your FTTC is ceased
Order FTTP. Job done.
She did suggest that I re-contract with TT and in a couple of months or so they will be announcing FTTP with VOIP and I could move to that without any fee to leave my new contract, just upgrade.
I'll be amazed if Talktalk residential launch a VOIP offering in the next few months.
They released another new Hub for FTTP customers fairly recently, the Amazon Eero 6 and Eero 6 Pro.
It does not have VOIP ports. They still have not launched a Hub with a VOIP port or to even trial such a service.
The last guy told you they were launching VOIP in August.
One thing the guy on their FTTP phone line did say when I said I needed a phone service as well as FTTP was that this might be available from TT by around August this year, now I don't know if there is any truth in this or whether this was just a sales pitch but just perhaps there is a grain of truth in it albeit VOIP rather that anything which would work in a power cut!
I don't understand why sales staff speculate on that kind of thing.
Large corporations like BT and Talktalk simply don't involve Margaret from sales in discussions on what products they will or won't sell in the future.