Yes, but I found my iPhone was getting pretty hot if I used it continuously so I bought a GSM router for about 5000baht from Banana and another SIM from AIS.
, you need an OA as you say, then an extension based on retirement. Unless you have a fetish for bureaucracy and spending long periods sat in government offices, I would highly encourage you to engage an agent. It’s all possible alone, but getting a bank account before you have a visa, which you require to apply for the visa, is the ultimate Catch-22. Some people manage it, bless their socks, but many more try and fail.
All joking aside, if you’re in the Chon Buri province I would highly recommend