Hi Geoff, unfortunately we have found it to be worse than you are being advised. We wanted a small mortgage for a project and have been refused any mortgage because John cannot get life insurance - he is 5 years post diagnosis and has been undetectable for 3 years but we couldn't find a company that was willing to cover him. I suppose in their eyes it is the equivalent of providing contents insurance for a house that has no front door.
Incidentally, this was the reason I decided against genetic testing a few years ago - as part of the counselling you have to go through beforehand it was explained to me that if I tested positive for the gene that causes brain tumours in our family, our children probably wouldn't be able to get mortgages or life insurance when they get to that stage.
Let us all know if you do find a willing company