It is unlikely you can use regular UK based insurance companies if you are not a UK resident. Different countries insure vehicles differently.
So, you have 2 options:
Find a local broker in the country where you reside that has been independently recommended by other expats. Or
Use a UK based broker that specialises in car insurance for UK expats.
Price is often the key factor, and premiums can vary hugely, But it may not be the only matter to consider. A broker may be better judged on how they handle a crisis should you have an accident.
You must be a UK resident to renew a UK driving licence.
Check the driving licence advice for the country you live in. Each country has its own driving licence rules.
Having a UK address is not enough. As an expat, you are not a UK resident. So, you will not be able to renew your driving licence in the UK.
If you rent a car using a UK address, your rental insurance is invalid as your driver’s licence is not valid [even with a UK address on it]. The insurance company will check where you live if you have an accident.
Although it is up to the individual to determine their country of residence, The DVLA application form for a new driving Licence [Form D1] specifically asks:
“Have you lived in another EC or EEA country in the last 12 months? If yes, which country.”
And immediately above Section 8 where you sign, you make a declaration that states:
“I understand that it is a criminal offence if I make, or anyone else makes, a false declaration to get a licence, and to do so can lead to prosecution and a fine of up to £2,500. I also understand it is an offence to fail to provide information which can lead to prosecution with a fine of up to £1,000.”
If in any doubt, seek independent legal advice.