Saige Bdot - Look at Delta or Korean with connection in Inchon to BKK. Both allow in the cabin with you with limitations. If you do this, please post what and how it worked for you.
Good question and I’m watching for the the right answer on this question too. I don’t have that situation, but I see myself needing to know this maybe in the future.
Along with a VPN server giving you an IP address for UK (or where ever you choose), also in the USA there are posta/mail companies that you can subscribe to and the address can be your legal address here in the USA......maybe UK or other countries have similar services. You can see your mail from anywhere online. The mail service will scan your incoming paper postal/mail to a PDF and then upload for you to view. The paper mail is stored by the company unless you want it shredded, or shipped to you. Another way to show your residence is in the UK.....if available.
Ok, but web sites can recognize your IP address from Thailand when you log in. If that is a problem, then a VPN can be set to any country with servers for your VPN service. I use NORD VPN but there are many others to use.