Maybe they have a house sitter.
3 seconds sound clip from the Home Alone 2: Lost in New York movie soundboard.
You can hear this line at 01:01:37 in the Blu-ray version of the movie.
Quote context
[...]
- He ran away from the hotel when they questioned him about the card.
- He must be so scared, Peter!
- I wonder if he'd know enough to go to my brother's place?
- Maybe they have a house sitter.
- I thought you said they were renovating?
- Hello?
[...]