Winter house rental

When is a good time to start looking for house rentals for January thru March? My husband and I are all set but some friends are thinking of comming down and all of the VRBO and rental agency sites never seem to have anything new. Some places seem to have been on those sites for over a year. Any ideas?

It depends on where you want to rent. My short term casita rentals in Ajijic village get booked 6 months to a year in advance especially for the high season. I just had a cancellation a few days ago for Jan/Feb so it went back on the block and I already have inquiries to book it.