That's a legal question rather than a tax question. My understanding is that you may not enter into a bad bargain in order to put assets beyond the reach of your creditors. In other words, if you sold your business at full value then fine, the creditors would simply take their share of the proceeds instead. If you sold it to a connected party for £1, then they may have a claim against you and/or the new owner for the assets which you have tried to remove from your possession. I am pretty sure that is the case with (for instance) settling something into trust.
However, I think you are getting a bit ahead of yourself. If you have not done so already, I would do the following things tomorrow:
Tell them you want to settle all tax you owe, as soon as possible
You stand to inherit part of the proceeds of your late father's estate sufficient to cover your liabilities as stated at this point but it may take some weeks for the proceeds to pay out
You will in the intervening period work to bring your tax affairs up to date.
You have been prevented from doing so in the normal course of events due to your partner's illness which can presumably be proven if and when the time comes
You expect that the outstanding returns will result in losses for tax purposes so at least some of the debt is not actually due but understand that HMRC will continue to try to collect the debt they estimate to be due until such time as it is displaced by a valid tax return.
Depending on the seniority/experience/disposition of the person who takes your call, you may get some sympathy and an agreement to postpone further action for x amount of weekes. Alternatively you may get someone who resolutely sticks to a script.
If the DMB officer starts to give you a hard time, or to suggest that it's too late for this kind of postponement, explain that you want him or her to note your file with the points as above.
This is because, when more serious action is being contemplated, your file should be reviewed by a more senior officer who SHOULD take your comments into consideration.
You should contact HMRC as soon as possible, since life is much more difficult once a debt is passed over to a separate debt recovery specialist (usually a firm of solicitors or similar) which is paid for results, not co-operation.