Hi again, I'm no expert on this so this is just how see it hopefully others will post later-I'm prepared to be corrected:
With critical illness broadly speaking they will pay out, as long as you've been honest I'm sure, a pretermined amount, before your death in order to assist in managing your condition. As far as I'm aware BUPA will get you sorted quicker for a medical problem. Life insurance can be level term meaning you get a level amount whether you die now or a few years down the line, usually more expensive than decreasing term life insurance, usually but not always linked to a mortgage, wherby the payment decreases in line with years to a predetermined date until you get nowt!-, usually the end of the mortgage if you died before you're mortgage ended this payment should cover the amount of the outstanding mortgage and should be used for this IMO!
Now this is where your opinion and research is needed. Yes insurance can be an option but there are other ways such as a savings account possibly and I know this point could be emotive -cancelling your BUPA payment (Use NHS) and using that and any other cash to fund the cash for your son. I'm no expert financial advisor and this is just a few thoughts to think on. I do hope that some others post on this thread and can perhaps help you further. Hopefully you have many years left! and your son in the fullness of time may/can seek employment whereupon he can save some money for himself.
Right off to work! hopefully by Monday you'll be inundated with advice TTFN
Paul