London and Victoria accepted my 5 year “clean driver” cover note from RSA when I left Motability for a year in 2018. Did not need to produce the letter as I assumed they (LV) have electronic access to the letter.
I use a comparison site and LV was one of the cheapest for my situation but gave them a quick call to make sure they would accept the cover note before pressing the “buy” button on the comparison site.
Sorry for your lose.