This past January Haunted Mansion Holiday stayed open through Sunday, January 11th, and then closed for overlay removal. I think it was because Frozen Fun officially debuted on January 7th, and Disney probably expected a lot of extra people flooding the parks. Also, some Southern California students didn't go back to school until 1/12.
This coming January I have a feeling HMH might stay open through Sunday, 1/10, and be closed by 1/11. Aladdin's final performance is on 1/10. Supposedly the Big Thunder Ranch and BBQ will be closing for good after 1/10. There is a chance (though no confirmation yet) that the Season of the Force event (with Hyperspace Mountain) could begin right after the holidays end on 1/6. So I tend to think that Disney may want to leave HMH up through that weekend. It will be closed for roughly 2 weeks, assuming that no further refurbishments and maintenance are needed beyond the overlay removal.
It's a Small World Holiday -- if it follows tradition -- should be open through January 24th or so, and then probably close on January 25th for its own overlay removal.