I have looked at the O-A Non-IMM Visa as an option. But as I would be required to use the Thai Embassy Washington DC but spend the bulk of my time in US in Florida, I would need up 2 months on the ground in US to get the O-A or spend considerable time to/from WashDC instead of the usual 3 weeks max that I now spend stateside. 

Edited August 21, 20187 yr by JLCrab

On ‎8‎/‎18‎/‎2018 at 7:53 PM, elviajero said:

I wouldn’t bother with applying for an extension of stay unless move permanently to Thailand.

 

If you get a Non ‘O-A’ visa you should, with planning, be able to come and go for nearly two years. At the end of the two years you can get another ‘O-A’ visa in the UK an repeat. 

 

Once/if you make a permanent move you can apply for an extension of stay within the last 30 days of any 1 year permit to stay.

And since you will be going back home regularly, you don't need to have the 800,000 in a Thai bank. Your money can stay in the UK if that is important to you. (As to just renewing your O-A every 2 years)