The chance you get asked is very very very tiny. Unless you have a long history of back to back stamps or tv entries. furthermore the rules for visa exempt entries is 10.000 baht or equivalent.

Fair enough, if that is a concern, get a tv. You do loose flexibility going this early. In my view it doesn't matter which office you use. It is just an extension

What is this proof of funds nonsense ? Op is arriving visa exempt, she will be stamped in no questions asked, that extention will cost 1900 baht, no questions asked again. No way someone on a tv is asked for proof of funds either, unless arriving at Sadoa, which might be quite the challenge from the uk...

There is absolutely no advantage in appling early. Apply a week before your 30 days are up, or better get a tv.

@Antoshka ********

amazing, like going back in time 10 years ago :) I nowadays use a Lao gsm sim, that way I have reliable coverage

Antoshka Anthony Wow, my AIS worked fine as far out from the river like this about ten years ago, nowadays the only place where it will actually pick up the Thai signal is at the river itself, walk about 100 meters out and the signal is gone. You must use something other than AIS for the signal to work that far out, as the family hotel is about 500 meters from the river, I never managed to get AIS to work in that place for the past ten years for sure. Family is not close to the consulate, you need a 10 minutes + taxi ride to get there.

It is fairly simple, the best time to arrive there is on Friday, you will be in and out in about 10 minutes. Yes you need to wait for the visa until Monday, but truth be told, Vientiane is a great city, and spending the weekend there is heaps of fun. Monday you will be in and out in ten minutes as well of course.

If you happen to go to Nong Khai, you might as well get another setv. It buys you 60 days, and Vientiane is a great city, not much places in Thailand come close.

They can enter Thailand with under 6 months validity, pretty sure Lao and Cambodia allow the same, this is hardly ever checked

1) no, the limit only applies to visa exempt entries. Visa holders are not limited

Yes you need a copy of both + 2 photos. There is a shop right next to the consulate that will do them for you