Inheritance tax for deemed domiciled

Hello. I am Italian national who has lived and been tax resident in the UK for 30+ years and have settle status since its inception post Brexit. I have always kept my domicile in Italy, where my father still lives, but have become "deemed domiciled" for Inheritance Tax, by virtue of the 15-out-of-20 years rule. What happens if I want to now leave the UK and go and live in Portugal for the rest of my life? I understand I am not allowed to come back for more than 90 days a year for a while. But what happens to my estate if I die soon after I move? Does the fact that I am Italian and never had a UK passport mean that my assets become immediately exempt from UK Inheritance tax? thank you in advance

Hi 

Please refer to How Inheritance Tax works: thresholds, rules and allowances

Thank you