After Pai we set out on an adventure to arrange the trip to Laos ourselves. There’s lots of companies that advertise taking you all the way there, but it´s LOTS cheaper, I repeat LOTS cheaper to do it yourselves. Just get tickets as you go along. I took a minivan from Pai to Chiang Mai, then a public bus to Chiang Rai (because the bus to Chiang Khong was full). The next day a public bus to Chiang Khong and the short trip over the river. Presto. Made it to Laos!
I crossed the border with Laos and instead of going to south, like most, I went north.