We will be flying in to Vientiane on Dec. 4 and want to go to Udon Thani the same day. Our plane arrives at 2:30 pm. I assumed that would be enough time to go to the Talat Sao bus station and hopefully catch the 4:30 bus, if not then the 6:00 bus. But then I read the buses get sold out 3 hours before departure time. Since we won't be staying in Vientiane, we can't ask our hotel to book or buy tickets. Could we get a mini-van from the airport? A taxi might cost too much. Any suggestions?