Most airports carry out maintenance during the night. A while back Dublin closed the main runway 10/28 between 00:00 - 05:30 every night for a number of weeks. They carry out maintainer between Feb-May so it doesn't affect flights in the summer which come in well after midnight. If BFS done this it wouldn't be a problem.
Was just looking at BFS on wikipedia and it says that thomson are starting flights to Rovaniemi (Lapland) [begins 10 December]
Only operate twice