Wow, that is a big trip coming along! Looking forward to follow it, having read your previous trip report.
As a foreigner living (albeit working, not retired) in Thailand, I think you should definitely spend more time here if you are considering retiring in Thailand. I would be happy to provide ideas for places to go, etc on DM if you like. And of course, let me know if you want to grab a beer when in BKK
Enjoy your trip!