Letterkenny Comhaltas has sessions Tuesday nights at Clanree Hotel, which is on the edge of town on the main road in the direction of Derry and Ballybofey.

I saw notices about fiddle meets at Kilcar on Saturdays. Kilcar is a small place and not far from Carrick (an Carraig) and Teelin so you can enquire when you are in the area.

I think there are still sessions at the Shamrock in Falcarragh on Sat, very near Gort a' Choirce (I believe the road signs for Gortahork will be in Irish).

Be wary of driving on Irish roads, especially at night. There is an atrocious road accident rate here and many of the fatal accidents have involved young drivers in country areas in the wee hours of the morning. You might drive carefully but the driver of the car near you might not.