Do you think it’s likely?
In my experience, birds scared away during a predator attack generally return early evening of the attack or very early the next morning. Hopefully there are survivors still in hiding.
Any small spaces they could be hiding in? Last month I came out to the coop a couple of times and something had terrified my chickens enough that they hid in any space they could find. Normally if they hear the rooster warning they just run for cover but these times they were literally jammed into every nook and cranny. We have a couple of smaller "coops" outside in the run that we used for mama hens/chicks and most were hiding there, or in the nesting boxes inside the main coop. A couple I found jammed into a small space behind one of the little coops and a fence. I would have never spotted them but I was trying to see if I could find any predator tracks in the snow and saw a small pile of feathers. Looking around I spotted the tip of a tail. Poor girls had melted snow dripping on them so I'm glad I was able to find them before nightfall. If you can, get out there and check every small space they could be hiding in. Best of luck, it is absolutely heartbreaking when something like this happens.
Can they survive during the night if they find a tree to roost in?
There are not really any small spaces in our coop but I will check. It is very heartbreaking but hopeful some could still come back.
They can if another predator doesn't find them and they are able to stay warm.
Absolutely. Depending of the area you are in (i.e.how many/types of predators you have, the temperatures you're dealing with etc, A few times I have missed a chicken/young cockerel/pullet outside of the coop at lights out and in the morning they are fine. Only once I came across a young cockerel with his feet frozen (not sure where he was hiding) but otherwise they are more than capable of surviving outside. Just a couple days ago I failed to check an outside 'coop' and a 3 month old cockerel spent the night out there at-20C. Perfectly fine.
