If you enrols both children in an international school approved for a one year ED visa, you might “piggyback” them on a dependent visa. Each for one child.
A METV -six months multiple entries tourist visa- is an option and gives up to nine months in Thailand.
Since you’re not past 50 years a retirement visa is not an option.
Then there’s something called Thai privilege visa for longer stays, quite expensive and you’re formally not allowed to do any work.
Then there’s a Long Term Residency visa if you qualify.
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