My ILs turned my husband's bedroom into a guestroom. But the people they really want to stay over most is me and him, plus one aunt, who is morbidly obese. Why is that relevant - because they put twins in, not a double or king!?!
We only live forty minutes away, so it's always been preferable to drive home than sleep in singles, and his aunt preferred to stay at ours too. MIL eventually redecorated with a double bed.
Double bed has the spongiest mattress in the world. I literally woke up with a bad hip at Christmas. They invited us to stay for NYE too, but I didn't want to start the new year in pain, so went sober instead.
Not to mention lack of bedside tables for a few years. This Christmas - bedside tables and lamps - no lightbulbs!
It's not a budget issue - MIL loves to redecorate, so the furniture is expensive and the bed is covered in expensive cushions. She just always looks miffed when we say that we'll go home, and just adds more cushions, as if that solves anything.
To add insult to injury, they've set up the spare room as a nursery for our son, but we haven't even got a comfortable fucking bed there.