It would have been late 2020 or early 2021, I got the car in June 2020 and the first snow I went out in it was literally undriveable, no grip whatsoever, even in just 1cm. I rang Motability but they never mentioned anything about being able to have them swapped out and stored, just said any alteration to the factory tyres would invalidate the insurance, typical Motability, depends who you get when you ring
The dimwits probably thought you were changing the wheels not just the tyres ?
I have not heard of any insurance company, voiding insurance just because some on has changed the tyres for a different brand or season type, so long they are compatible with the vehicle type and load.