Here's my evaluation on this:
*Check the ground. The areas that I seeded are thawing and somewhat soft – this is good.
*It’s freezing today - not so good. Grass seed could die off a little in the freezing temperatures. I don’t know at what temperature the grass seed can die, but I do know that the percentage of germination diminishes when it freezes and I know that it won’t all die. So you might not get the germination you would if the temperatures were warmer. Instead of 98% you might get 80%, so plan on that when putting the seed down.
*Grass seed likes a cool germination period, so don’t worry that it’s too cold, unless of course it’s like 10 degrees F.
*Spread the seed and walk away. Don’t water it unless you are in a drought, then my advise is don’t bother to even put the seed down. If it doesn’t all take, you have nothing to loose. Remember I’m not suggesting starting a new lawn like this, I’m only suggesting to over seed a little to improve the lawn for the coming season. Don’t spend a lot of money on this.
*Last but not least if it snows again, don’t worry about it. If there a deluge of rain, the seed may wash away if the area that you seeded is on a slope. It doesn’t usually all wash away though and you can fix it when the weather gets a little better.