Hi Brydo, about 8 years ago I was in exactly the same position. I had a Volvo V40 which was getting tougher and tougher getting in/out of. I contacted Motability to explain this and I had to get a wheelchair in and out of the car too. They were very accomodating and changed it for a Nissan Qashqai mid ontract.
I don’t know if they have changed their rules but just contact them and explain, I am sure they will agree as your circumstances hae changed I assume.
Current car 2019 Ford Kuga 1.5T Titanium X Edition (White)
On order new Vauxhall Grandland Ultimate 1.2 Turbo (Ruby Red)