I think the most surreal was my DH's first Christmas with my mum's family.
First, we learned that DAunt#1 and family, who lived in the same small town as DGran, had got a cheap deal to the US and would be spending Christmas abroad while we kept DGran company.
Then the plane we were supposed to catch was grounded by fog and we had to travel by coach and ferry - taking a day and a half instead of a couple of hours to get there.
Then we realised that we'd got a cheap deal on the hotel we stayed in because it had officially closed. Although the hotel wasn't staffed any more, there was a note telling us we could still use the keys to let ourselves into our rooms for the duration of our stay - "just post them through the letterbox when you leave!"
The heating was dodgy and the kitchen was locked, so we had nothing to eat or drink apart from the tiny teamaking facilities in the room and a couple of stale rolls at the reception desk.
We then realised that although we'd booked a hotel near DGran's house (which wasn't particularly near anything else), DAunt#2 had decided at the last minute to have her to stay (but hadn't told Mum or DAunt#1 about this) - DAunt#2 lives 10 miles from my parents' house. DAunt#3 was away skiing and wouldn't be back until Christmas day.
DMum and DDad got food poisoning and spent Christmas in bed. Meanwhile the town had had a big 'keep Christmas for the family' campaign and closed all its shops and restaurants on the 23rd December - meaning that DH and I lived on Quavers from the hotel's remaining vending machine for two days.
Boxing day at DAunt #3's house felt like a liberation..