Phu reah and Dan Sai are very nice spots.
We were in Dan Sai for the Phitakorn festivle where the sleepy town gets 10's of thousand s of visitors.
The Phu reah resort just outside of Loei on the way to Phu rea is a very nice place to stay with good rooms good food and good 'thai' music.
Good places to stay on the way to Vientiane , nong khai or ubon as it cuts a lot of distance off the trip by short cutting the leg from uttradit.
mark