I've done it with mixed results. More poor than good. You take the chance of heavy rains washing the seed away. A good warm spell could let the seed germinate, and it won't survive once the temps. drop. I'd wait till spring unless the customer insists.
I am doing dormant seeding this year using my Hydroseeder. I have seen it done late in the season and it looks pretty good in the spring. NO Pre Emergent control in the spring unless you use Siduron or Tupersan.
I would rather wait until the spring myself but this is for contractors that need to get paid.