looking at 1-2 weeks in hanoi; 8 days total for me. for current location evidence i included my boarding pass into the city, my vietnam visa + stamp in passport, my airbnb reservation, and a photo of myself (time stamped + location) in front of said airbnb. i provided just about everything others have mentioned to avoid getting asked for additional documents. i’ve also heard 1-2 week turnovers in vientiane, but cannot speak from experience.