Janey, The festival doesn't really make much impact on the pub session scene,but all the artists stay in the central hotel,and there is a club stage in there with performances till the wee small hours,and more informal sessions than you can shake a fiddle-bow at!
Be warned-the club gets VERY busy at w/ends...so get a ticket and go early...(during the week it's quieter and free to get in.)....i think that having a concert ticket for that day entitles you to get into the club the same night.
The club kicks off about 11pm...and continues till breakfast!