I may be wrong but a few years ago on autumnwatch they showed some large roosts coming in. I think once they get down they more or less settle close to each other to keep the heat and of course there will not be much room with the thousands of them, but continue calling until settled but as long as they have protection from the weather and predators they are happy.
From RSPB site
"
During the winter, starlings live in flocks throughout the day, travelling between feeding sites. They have spare time for preening and loafing, usually close to the feeding areas at noisy gatherings called daytime roosts. Day roosts are normally at exposed places such as tops of trees, where the birds have a good all-round visibility.
Starlings feed up to 20 miles from their winter roost, but return each evening. In late afternoon feeding flocks coalesce into progressively larger flocks as they move towards the roost. Large pre-roost assemblages form in places where the birds can get one last meal before nightfall. At dusk birds from these assemblies fly, often in a swirling cloud-like formation, to the roost.
Woods are the commonest roost sites, but reedbeds, cliffs, buildings and industrial structures are used. Protection from weather and predators are important criteria in the choice of a roost. A large roost can contain hundreds of thousands of birds.
Once inside the roost, starlings take their time to settle and are quite vocal. Noise levels increase again towards dawn, and the birds leave in waves. These flocks can be detected on radar, which allows detailed monitoring of the movements of the birds. "
