I don't think I have every received 100% of my 1099's before end of January, despite that being a requirement. I'm lucky if I have them all by end of February, which usually includes a revision or two.
I keep very good records of my earnings but have also found that many of the companies I work with don't, and the 1099 totals don't always match my records. I have also had issues with the IRS pushing back when the numbers didn't match, so I tend to wait on tax filing until I have them all and make sure they are correct.