Very sorry to read of your sad news. Hope things work out. It shows how important wills are in Thailand. They are very easy to make and all couples should make them whilst they can.
My point was NOT about having to have health insurance, my point was that everyone should have health insurance, and at his age that might be a problem. Either that or a lot in the bank.
I have had gites in France and houses in Thailand. In Thailand it would be resort. Don't think of doing anything like it until you have lived here a while. If a resort is a dream, buy one or make one, but rent first for at least a year. You could think of homestay, but rent first. Rent first rent first. Thailand is as varied by region as France is. Get to know it first. Otherwise you can make a big mistake, like all the Brits who relocated to dying medical deserts in the Creuse and vienne