My relative was in a similar situation in reasonably recent times. It was long before Covid, so leaving that aside, he went for initial appointment and the decision was made to remove the remaining teeth and have new full dentures. An impression was taken and sent off for manufacture.
He goes home with old teeth and old dentures.
Next visit which was a couple of weeks later he goes again and has the teeth removed, but keeps old dentures, so lives with a few odd gaps for a short time.
Final visit the following week he has the new dentures fitted. Sadly they needed an alteration, so he went home yet again with his old dentures, which he gets to keep anyway, for a further week.
Final visit all was well and all done on NHS. The charge was band 3.
https://www.nhs.uk/nhs-services/dentists/dental-costs/how-much-will-i-pay-for-nhs-dental-treatment/