Christmas Eve viewing: Outnumbered, BBC1<br/>Lapland, BBC1

OK. It's 8.30. That's Christmas over." It was a dream of sorts, uttered by a woman who knew she was at the sharp end of the wrapping-paper-clearance, greasy-pots end of the annual celebration and, just in case you were wondering, it was half past eight in the morning, as Sue from Outnumbered began the familiar cat-drive involved in getting the family to the airport on time.

This year, she had vowed, it was going to be different. They were going away for a short break in the Canaries after a stressful few months that had included bedding infestation and over-reaction by the social services. This being Outnumbered, of course, several towering hurdles stood between that consummation and the chaotic starting line of Christmas breakfast. For the moment, nobody is going anywhere. Ben is a little disappointed with the contents of The Dangerous Book for Boys ("There's nothing about firework shoes in here. Look. 'Grinding an Italic Nib'. What's dangerous about that?") Karen, the six-year old, is in the bathroom shaving (for some reason not explained) and Sue herself is fretting about whether to leave Grandad in hospital over the festive season. "We need a break from Mum needing a break," pleaded Jake meaningfully when cancellation was mooted.

It must be a little wearing maintaining this level of anxiety and there are some signs that Outnumbered is feeling its age. This is partly because the children themselves are growing up but can't entirely be allowed to do so if the comic balance is to be maintained (if only they were drawn like Bart and Lisa). In fact, now and then, there's a sense that they've become caricatures of themselves, straining for effects that seemed entirely fresh in the first series. Characters in a comedy can't really learn, of course, but the underlying naturalism of Outnumbered (its implicit promise that parenthood really is like this) also results in an odd strain between laughter and credulity. Wouldn't they have packed the night before, you find yourself asking, and perhaps dropped in on Grandad on the way to the airport when everything was sorted? Are they being clueless by design? The answer to the last question is "Yes, idiot, they're made-up", but that isn't what you want to be thinking about in a comedy.

It's still funnier than any other family sitcom, as good at sight gags (Ben marching purposefully past the window with a pickaxe at one point) as it is with dialogue. "Oh, look... there's the Queen doing her Christmas thing," said Grandpa brightly, watching the television in his hospital room. "No, Grandad," replied Jake patiently, "that's John Simpson." And though I don't buy for a second that parents this scarred would have let Ben make the sandwiches for the car journey unsupervised (he offers a choice of treacle and mayonnaise or chocolate and stilton bap), they essentially earned the moment of uplift with which all Christmas programmes are obliged to end – in this case, a family sing-song round Grandad's hospital bed.

In Lapland – chillingly described as "heartwarming" in the Radio Times – it was the Northern Lights that provided the cure-all for family dysfunction, uniting a bickering Birkenhead family in innocent wonder at the end of a trip to visit Santa. Michael Wynne's drama had been so sour and bad-tempered up to this point, though, that the sudden swerve into bonhomie felt deeply unconvincing. One rapprochement – between a beleaguered husband and his endlessly whining wife – came about because he finally lost his patience and snapped, "Will you shut your fat gob for once!" a remark that I'm sure spoke for many viewers but seemed implausible as a catalyst for festive peace. There were some good lines, but I still came out thinking Mandy's early grumble had been a hazardous hostage to fortune: "Christmas," she said winningly, "is all about sitting on a sofa watching shite and eating crap."