Right, trailing/dependent spouse, 800K in one account with only that spouse's name on that account. That's what we do. There are pros & cons to having it under one spouse versus each having their own extension with their own 800K in the bank. Biggest risk may be that life can be come tough quickly for the dependent spouse if something happens to the primary spouse with the money in their name.
When I go to Bangkok Bank ATMs, I can withdraw almost any amount beyond the basic choices like it presents, like 700 Baht - for that, it gives me a 500 and 2 100's. It you choose "other amount", you can specify to get something besides a factor of 1000. Works like a charm when I need smaller currency.
Right - 2 ways to get to the embassy - fly into Vientiane (though not a direct flight) or fly to Udon Thani and trek in from there. Just comparing the ease of each option, or even having them go to Kuala Lampur, but that also has its own pros/cons.