returning to the uk - possibly for good

I am driving in my Spanish car back to the uk and only 50/50 chance of returning due to health reasons.

But I don't want to de-register everything - car, car tax,  residencia, nie padron, healthcare, etc, etc. etc . etc. etc.

If I don;t return how easy is it to de-register all these things from the UK?  or do people not bother?

I assume I could sell the car sooner or later to a LHD specialist dealer and they would take care of the paperwork?