This is probably the 2009 film, The Blackout.
it's Christmas eve and westphalia is under quakes and severe high temperatures with power surges going around the city( Los Angeles that is) . Scientists can't figure it out. There's a Christmas party in a tenement block, and the couples presented are living in the same building - 1 family (man + woman + man's brother + 2 kids boy and girl) , 1 about-to-get-divorced-couple, 1 about-to-get-married-couple, and some random dudes and girls. The newsman tells the power-surges are connected with the temperature and the quakes.
Mom and dad are trying to have fun(in bed) but the kids find them out and they get sent to the basement to bring up their presents. Nasty creature eats their guts.
There's an agoraphobic guy at the 2nd floor, friend with the superintendent and the electrician, and he's a master in discovery channel and electronics and communications. Electrician "Ralph" gets torn to bits. The party is ruined, more creatures come and claim lives. Some guy's brother tries something he saw on TV ("Hey the creatures might be photosensitive" ) but he gets a big head-shot and dies. The little girl is not dead - apparently she managed to survive ( somehow I have no idea ) and she got in a defunct elevator ( again HOW is a big question ). The group manages to kill 2 creatures, find out the main building entrance is blocked and head for the roof. They go through that defunct elevator's shaft and find out the little girl.
There is a better (but still critical) review here that includes some still image including the creatures.
I think found with a search for
horror film Christmas basement creatures, which led to this Bloody Disgusting list of Christmas horror films, wherein I searched for "basement".