Hopefully there is some berries and crab apples for them.

I also saw a large group of Robins about two weeks ago in West Central IL. I can't help but feel that they made an unwise choice with the recent blizzard hitting us.

I do have Robins here now beck. The males are really grouchy and establishing territory already. They are actually coming to my saucer feeders and taking dried fruit, especially dried cherries. You could buy a bag of dried cherries and put some out in a saucer for them.

I saw one last week here in N.W. Ohio.

None here yet thank God! They will eat moistened Cat kibble. I was feeding a stray years ago when a late April stom hit. The snow had soaked the cat food and Robins were flocking around the bowl like little pigs.

I think seeing robins in winter in Il depends largely on what habitat you have around, and yes, how far north you are. I am in south-central Il, Jefferson County, and I don't ever recall a winter here where you couldn't find large hordes of robins holed up in deeper woods or along river corridors. I think that must be the key: the ones that do stay have a hard time finding adequate shelter/ food in backyards during the winter months so they are still here, just not as visible as they would be during the rest of the year.
I just watched one such group about a month back, noisily flocking about the edges of the creek where the ice was melted and they had access to the water. It was a good year for hackberries here and the combination of easy food and water often makes this area a hotspot for wintering robins.
My preferred signs of spring? Barred owls on eggs! Harbinger-of-sping blooming on the forest floor!

Patience!

My sister and I were talking about this yesterday. She said she had a whole bunch in her backyard. they were all around a heated water bowl getting water.

Extreme S.E. Missouri.