Today only a 200 km bus-ride from Vang Vieng to Luang Prabang. That can't be too challenging, can it? Actually, our expensive bus turned out to be fully packed with foreigners and legroom was a bit of an issue. Also, apparently it is possible to take more than 6 hours to travel 200 kilometers. (Then there was a mountain in between)
Eventually did make it though, found a guesthouse, had dinner, looked around a bit at night and then passed out in bed.