Gutted to hear this, James. It sounds like you've already got a good grasp of the priorities going forward. If you need any help making sense of any medical advice you guys get in the weeks/months ahead, feel free to DM me.
It seems crass to say it now, but I’m definitely going to need advice on inheritance though,
Not a solicitor or accountant, but have looked into this to a moderate degree.I think there's be no IHT. 1) The gift would be liable for IHT but gets calculated on the total estate. So if under no IHT.https://www.moneyhelper.org.uk/en/family-and-care/death-and-bereavement/gifts-and-exemptions-from-inheritance-taxhttps://www.gov.uk/guidance/work-out-inheritance-tax-due-on-gifts2) Defined contribution pension would be IHT freehttps://www.gov.uk/tax-on-pension-death-benefits
Gifts use up the £325,000 tax free allowance first. Any unused threshold left after this can be used by the estate of the person who died.
He should be able to take his whole pot tax free if he has that prognosis, he'd need to provide signed correspondence from a Doctor confirming so and then it'd be reviewed by the Scheme Trustees, and it is Scheme Dependent, but it is possible. It isn't automatic though so he'd need to get in touch ASAP to start the process