Don't dismiss Nonthaburi
My wife and I owned our condo in Bangkok for about 15 years. During that time we lived in Korea for two years and China for three years. When we returned from China last year, it was time for me to retire.
We sold the condo in Bangkok and rented a condo in Nonthaburi while we looked for a house in Isaan to buy. The MRT Purple Line made living in Nonthaburii very convenient. We were a two-minute walk from an MRT station. My part time job and shopping centers were one or two MRT stops away. Getting to and from my embassy, the airports, and our prior home was easy. The immigration office in Nonthaburi was an attractive alternative to Chaengwattana.
People were nice. I have early stage Parkinson's and once fell into some thorny bushes and could not free myself. A motorcycle policeman freed me and seemed concerned only about my health. The MRT staff were very helpful on days I used a cane.
We seriously considered moving to Nonthaburi instead of Isaan. We're now settling down in our new home near the Buriram-Surin border but Nonthaburi was a wonderful stepping stone from Bangkok to Isaan.
James