@Zay ************
you may still be able to get a visa on arrival. Ask them about this before you get stamped in, you need to get it before you get an entry stamp. This will give you 30 days and is extendable. There is a good chance you could get your DTV within 14 days but if you have to wait for a statement this would give you a bit more breathing room.
If you do end up on the 14 days, ask them if they can expedite it, there are reports that they can. Worst case if you had to, you could do a border run at the end of the 14 days but this does risk rejection and it would probably be high in Vientiane where they bring you in for an interview typically on the day they issue, so they'd be able to see this in your passport if you did it.